diff --git a/build/android/liblinphone_tester.mk b/build/android/liblinphone_tester.mk
index ee2018621..d92bb60b5 100644
--- a/build/android/liblinphone_tester.mk
+++ b/build/android/liblinphone_tester.mk
@@ -18,7 +18,8 @@ common_SRC_FILES := \
 	transport_tester.c \
 	player_tester.c \
 	dtmf_tester.c \
-	accountmanager.c
+	accountmanager.c \
+	offeranswer_tester.c
 
 common_C_INCLUDES += \
         $(LOCAL_PATH) \
diff --git a/coreapi/bellesip_sal/sal_op_impl.c b/coreapi/bellesip_sal/sal_op_impl.c
index f9647f7ad..5c953ffc5 100644
--- a/coreapi/bellesip_sal/sal_op_impl.c
+++ b/coreapi/bellesip_sal/sal_op_impl.c
@@ -235,7 +235,10 @@ int sal_ping(SalOp *op, const char *from, const char *to){
 void sal_op_set_remote_ua(SalOp*op,belle_sip_message_t* message) {
 	belle_sip_header_user_agent_t* user_agent=belle_sip_message_get_header_by_type(message,belle_sip_header_user_agent_t);
 	char user_agent_string[256];
-	if(user_agent && belle_sip_header_user_agent_get_products_as_string(user_agent,user_agent_string,sizeof(user_agent_string))>0) {
+	if (user_agent && belle_sip_header_user_agent_get_products_as_string(user_agent,user_agent_string,sizeof(user_agent_string))>0) {
+		if (op->base.remote_ua!=NULL){
+			ms_free(op->base.remote_ua);
+		}
 		op->base.remote_ua=ms_strdup(user_agent_string);
 	}
 }
diff --git a/coreapi/callbacks.c b/coreapi/callbacks.c
index c43c84479..2d9ff58ae 100644
--- a/coreapi/callbacks.c
+++ b/coreapi/callbacks.c
@@ -96,7 +96,23 @@ static void prepare_early_media_forking(LinphoneCall *call){
 	if (call->videostream){
 		rtp_session_set_symmetric_rtp(call->videostream->ms.sessions.rtp_session,FALSE);
 	}
+}
 
+void linphone_call_update_frozen_payloads(LinphoneCall *call, SalMediaDescription *result_desc){
+	SalMediaDescription *local=call->localdesc;
+	int i;
+	for(i=0;i<result_desc->nb_streams;++i){
+		MSList *elem;
+		for (elem=result_desc->streams[i].payloads;elem!=NULL;elem=elem->next){
+			PayloadType *pt=(PayloadType*)elem->data;
+			if (is_payload_type_number_available(local->streams[i].already_assigned_payloads, payload_type_get_number(pt), NULL)){
+				/*new codec, needs to be added to the list*/
+				local->streams[i].already_assigned_payloads=ms_list_append(local->streams[i].already_assigned_payloads, payload_type_clone(pt));
+				ms_message("LinphoneCall[%p] : payload type %i %s/%i fmtp=%s added to frozen list.",
+					   call, payload_type_get_number(pt), pt->mime_type, pt->clock_rate, pt->recv_fmtp ? pt->recv_fmtp : NULL);
+			}
+		}
+	}
 }
 
 void linphone_core_update_streams(LinphoneCore *lc, LinphoneCall *call, SalMediaDescription *new_md){
@@ -181,6 +197,7 @@ void linphone_core_update_streams(LinphoneCore *lc, LinphoneCall *call, SalMedia
 	if (call->state==LinphoneCallPausing && call->paused_by_app && ms_list_size(lc->calls)==1){
 		linphone_core_play_named_tone(lc,LinphoneToneCallOnHold);
 	}
+	linphone_call_update_frozen_payloads(call, new_md);
 	end:
 	if (oldmd)
 		sal_media_description_unref(oldmd);
diff --git a/coreapi/linphonecall.c b/coreapi/linphonecall.c
index 498c0accf..3c9dfaf90 100644
--- a/coreapi/linphonecall.c
+++ b/coreapi/linphonecall.c
@@ -228,35 +228,154 @@ void linphone_call_set_authentication_token_verified(LinphoneCall *call, bool_t
 	propagate_encryption_changed(call);
 }
 
-static MSList *make_codec_list(LinphoneCore *lc, const MSList *codecs, int bandwidth_limit,int* max_sample_rate, int nb_codecs_limit){
-	MSList *l=NULL;
+static int get_max_codec_sample_rate(const MSList *codecs){
+	int max_sample_rate=0;
 	const MSList *it;
-	int nb = 0;
-	if (max_sample_rate) *max_sample_rate=0;
 	for(it=codecs;it!=NULL;it=it->next){
 		PayloadType *pt=(PayloadType*)it->data;
-		if (pt->flags & PAYLOAD_TYPE_ENABLED){
-			int sample_rate = payload_type_get_rate(pt);
+		int sample_rate;
+		
+		if( strcasecmp("G722",pt->mime_type) == 0 ){
+			/* G722 spec says 8000 but the codec actually requires 16000 */
+			sample_rate = 16000;
+		}else sample_rate=pt->clock_rate;
+		if (sample_rate>max_sample_rate) max_sample_rate=sample_rate;
+	}
+	return max_sample_rate;
+}
 
-			if( strcasecmp("G722",pt->mime_type) == 0 ){
-				/* G722 spec says 8000 but the codec actually requires 16000 */
-				ms_debug("Correcting sample rate for G722");
-				sample_rate = 16000;
-			}
-
-			if (bandwidth_limit>0 && !linphone_core_is_payload_type_usable_for_bandwidth(lc,pt,bandwidth_limit)){
-				ms_message("Codec %s/%i eliminated because of audio bandwidth constraint of %i kbit/s",
-					   pt->mime_type,pt->clock_rate,bandwidth_limit);
-				continue;
-			}
-			if (linphone_core_check_payload_type_usability(lc,pt)){
-				l=ms_list_append(l,payload_type_clone(pt));
-				nb++;
-				if (max_sample_rate && sample_rate>*max_sample_rate) *max_sample_rate=sample_rate;
+static int find_payload_type_number(const MSList *assigned, const PayloadType *pt){
+	const MSList *elem;
+	const PayloadType *candidate=NULL;
+	for(elem=assigned;elem!=NULL;elem=elem->next){
+		const PayloadType *it=(const PayloadType*)elem->data;
+		if ((strcasecmp(pt->mime_type, payload_type_get_mime(it)) == 0)
+			&& (it->clock_rate==pt->clock_rate)
+			&& (it->channels==pt->channels || pt->channels<=0)) {
+			candidate=it;
+			if ((it->recv_fmtp!=NULL && pt->recv_fmtp!=NULL && strcasecmp(it->recv_fmtp, pt->recv_fmtp)==0)
+				|| (it->recv_fmtp==NULL && pt->recv_fmtp==NULL)){
+				break;/*exact match*/
 			}
 		}
-		if ((nb_codecs_limit > 0) && (nb >= nb_codecs_limit)) break;
 	}
+	return candidate ? payload_type_get_number(candidate) : -1;
+}
+
+bool_t is_payload_type_number_available(const MSList *l, int number, const PayloadType *ignore){
+	const MSList *elem;
+	for (elem=l; elem!=NULL; elem=elem->next){
+		const PayloadType *pt=(PayloadType*)elem->data;
+		if (pt!=ignore && payload_type_get_number(pt)==number) return FALSE;
+	}
+	return TRUE;
+}
+
+static void linphone_core_assign_payload_type_numbers(LinphoneCore *lc, MSList *codecs){
+	MSList *elem;
+	int dyn_number=lc->codecs_conf.dyn_pt;
+	for (elem=codecs; elem!=NULL; elem=elem->next){
+		PayloadType *pt=(PayloadType*)elem->data;
+		int number=payload_type_get_number(pt);
+		
+		/*check if number is duplicated: it could be the case if the remote forced us to use a mapping with a previous offer*/
+		if (number!=-1 && !(pt->flags & PAYLOAD_TYPE_FROZEN_NUMBER)){
+			if (!is_payload_type_number_available(codecs, number, pt)){
+				ms_message("Reassigning payload type %i %s/%i because already offered.", number, pt->mime_type, pt->clock_rate);
+				number=-1; /*need to be re-assigned*/
+			}
+		}
+		
+		if (number==-1){
+			while(dyn_number<127){
+				if (is_payload_type_number_available(codecs, dyn_number, NULL)){
+					payload_type_set_number(pt, dyn_number);
+					dyn_number++;
+					break;
+				}
+				dyn_number++;
+			}
+			if (dyn_number==127){
+				ms_error("Too many payload types configured ! codec %s/%i is disabled.", pt->mime_type, pt->clock_rate);
+				payload_type_set_enable(pt, FALSE);
+			}
+		}
+	}
+}
+
+static bool_t has_telephone_event_at_rate(const MSList *tev, int rate){
+	const MSList *it;
+	for(it=tev;it!=NULL;it=it->next){
+		const PayloadType *pt=(PayloadType*)it->data;
+		if (pt->clock_rate==rate) return TRUE;
+	}
+	return FALSE;
+}
+
+static MSList * create_telephone_events(LinphoneCore *lc, const MSList *codecs){
+	const MSList *it;
+	MSList *ret=NULL;
+	for(it=codecs;it!=NULL;it=it->next){
+		const PayloadType *pt=(PayloadType*)it->data;
+		if (!has_telephone_event_at_rate(ret,pt->clock_rate)){
+			PayloadType *tev=payload_type_clone(&payload_type_telephone_event);
+			tev->clock_rate=pt->clock_rate;
+			/*let it choose the number dynamically as for normal codecs*/
+			payload_type_set_number(tev, -1);
+			if (ret==NULL){
+				/*But for first telephone-event, prefer the number that was configured in the core*/
+				if (is_payload_type_number_available(codecs, lc->codecs_conf.telephone_event_pt, NULL)){
+					payload_type_set_number(tev, lc->codecs_conf.telephone_event_pt);
+				}
+			}
+			ret=ms_list_append(ret,tev);
+		}
+	}
+	return ret;
+}
+
+typedef struct _CodecConstraints{
+	int bandwidth_limit;
+	int max_codecs;
+	MSList *previously_used;
+}CodecConstraints;
+
+static MSList *make_codec_list(LinphoneCore *lc, CodecConstraints * hints, const MSList *codecs){
+	MSList *l=NULL;
+	MSList *tevs=NULL;
+	const MSList *it;
+	int nb = 0;
+
+	for(it=codecs;it!=NULL;it=it->next){
+		PayloadType *pt=(PayloadType*)it->data;
+		int num;
+		
+		if (!(pt->flags & PAYLOAD_TYPE_ENABLED))
+			continue;
+		if (hints->bandwidth_limit>0 && !linphone_core_is_payload_type_usable_for_bandwidth(lc,pt,hints->bandwidth_limit)){
+			ms_message("Codec %s/%i eliminated because of audio bandwidth constraint of %i kbit/s",
+					pt->mime_type,pt->clock_rate,hints->bandwidth_limit);
+			continue;
+		}
+		if (!linphone_core_check_payload_type_usability(lc,pt)){
+			continue;
+		}
+		pt=payload_type_clone(pt);
+		
+		/*look for a previously assigned number for this codec*/
+		num=find_payload_type_number(hints->previously_used, pt);
+		if (num!=-1){
+			payload_type_set_number(pt,num);
+			payload_type_set_flag(pt, PAYLOAD_TYPE_FROZEN_NUMBER);
+		}
+		
+		l=ms_list_append(l, pt);
+		nb++;
+		if ((hints->max_codecs > 0) && (nb >= hints->max_codecs)) break;
+	}
+	tevs=create_telephone_events(lc,l);
+	l=ms_list_concat(l,tevs);
+	linphone_core_assign_payload_type_numbers(lc, l);
 	return l;
 }
 
@@ -395,9 +514,16 @@ void linphone_call_update_local_media_description_from_ice_or_upnp(LinphoneCall
 #endif  //BUILD_UPNP
 }
 
+static void transfer_already_assigned_payload_types(SalMediaDescription *old, SalMediaDescription *md){
+	int i;
+	for(i=0;i<old->nb_streams;++i){
+		md->streams[i].already_assigned_payloads=old->streams[i].already_assigned_payloads;
+		old->streams[i].already_assigned_payloads=NULL;
+	}
+}
+
 void linphone_call_make_local_media_description(LinphoneCore *lc, LinphoneCall *call){
 	MSList *l;
-	PayloadType *pt;
 	SalMediaDescription *old_md=call->localdesc;
 	int i;
 	int nb_active_streams = 0;
@@ -406,6 +532,7 @@ void linphone_call_make_local_media_description(LinphoneCore *lc, LinphoneCall *
 	LinphoneAddress *addr;
 	char* local_ip=call->localip;
 	const char *subject=linphone_call_params_get_session_name(call->params);
+	CodecConstraints codec_hints={0};
 
 	linphone_core_adapt_to_network(lc,call->ping_time,call->params);
 
@@ -439,9 +566,11 @@ void linphone_call_make_local_media_description(LinphoneCore *lc, LinphoneCall *
 		md->streams[0].ptime=call->params->down_ptime;
 	else
 		md->streams[0].ptime=linphone_core_get_download_ptime(lc);
-	l=make_codec_list(lc,lc->codecs_conf.audio_codecs,call->params->audio_bw,&md->streams[0].max_rate,-1);
-	pt=payload_type_clone(rtp_profile_get_payload_from_mime(lc->default_profile,"telephone-event"));
-	l=ms_list_append(l,pt);
+	codec_hints.bandwidth_limit=call->params->audio_bw;
+	codec_hints.max_codecs=-1;
+	codec_hints.previously_used=old_md ? old_md->streams[0].already_assigned_payloads : NULL;
+	l=make_codec_list(lc, &codec_hints, lc->codecs_conf.audio_codecs);
+	md->streams[0].max_rate=get_max_codec_sample_rate(l);
 	md->streams[0].payloads=l;
 	nb_active_streams++;
 
@@ -453,7 +582,10 @@ void linphone_call_make_local_media_description(LinphoneCore *lc, LinphoneCall *
 		md->streams[1].rtcp_port=call->media_ports[1].rtcp_port;
 		md->streams[1].proto=md->streams[0].proto;
 		md->streams[1].type=SalVideo;
-		l=make_codec_list(lc,lc->codecs_conf.video_codecs,0,NULL,-1);
+		codec_hints.bandwidth_limit=0;
+		codec_hints.max_codecs=-1;
+		codec_hints.previously_used=old_md ? old_md->streams[1].already_assigned_payloads : NULL;
+		l=make_codec_list(lc, &codec_hints, lc->codecs_conf.video_codecs);
 		md->streams[1].payloads=l;
 		nb_active_streams++;
 	}
@@ -468,7 +600,10 @@ void linphone_call_make_local_media_description(LinphoneCore *lc, LinphoneCall *
 		md->streams[i].proto = call->biggestdesc->streams[i].proto;
 		md->streams[i].type = call->biggestdesc->streams[i].type;
 		md->streams[i].dir = SalStreamInactive;
-		l = make_codec_list(lc, lc->codecs_conf.video_codecs, 0, NULL, 1);
+		codec_hints.bandwidth_limit=0;
+		codec_hints.max_codecs=1;
+		codec_hints.previously_used=NULL;
+		l = make_codec_list(lc, &codec_hints, lc->codecs_conf.video_codecs);
 		md->streams[i].payloads = l;
 	}
 
@@ -481,6 +616,7 @@ void linphone_call_make_local_media_description(LinphoneCore *lc, LinphoneCall *
 	linphone_call_update_local_media_description_from_ice_or_upnp(call);
 	linphone_address_destroy(addr);
 	if (old_md){
+		transfer_already_assigned_payload_types(old_md,md);
 		call->localdesc_changed=sal_media_description_equals(md,old_md);
 		sal_media_description_unref(old_md);
 	}
diff --git a/coreapi/linphonecore.c b/coreapi/linphonecore.c
index ef4133d87..2543cb007 100644
--- a/coreapi/linphonecore.c
+++ b/coreapi/linphonecore.c
@@ -982,12 +982,13 @@ static void rtp_config_read(LinphoneCore *lc)
 	linphone_core_set_avpf_mode(lc,lp_config_get_int(lc->config,"rtp","avpf",0));
 }
 
-static PayloadType * find_payload(RtpProfile *prof, const char *mime_type, int clock_rate, int channels, const char *recv_fmtp){
+static PayloadType * find_payload(const MSList *default_list, const char *mime_type, int clock_rate, int channels, const char *recv_fmtp){
 	PayloadType *candidate=NULL;
-	int i;
 	PayloadType *it;
-	for(i=0;i<RTP_PROFILE_MAX_PAYLOADS;++i){
-		it=rtp_profile_get_payload(prof,i);
+	const MSList *elem;
+	
+	for(elem=default_list;elem!=NULL;elem=elem->next){
+		it=(PayloadType*)elem->data;
 		if (it!=NULL && strcasecmp(mime_type,it->mime_type)==0
 			&& (clock_rate==it->clock_rate || clock_rate<=0)
 			&& (channels==it->channels || channels<=0) ){
@@ -1009,7 +1010,20 @@ static PayloadType * find_payload(RtpProfile *prof, const char *mime_type, int c
 	return candidate;
 }
 
-static bool_t get_codec(LinphoneCore *lc, const char* type, int index, PayloadType **ret){
+static PayloadType* find_payload_type_from_list(const char* type, int rate, int channels, const MSList* from) {
+	const MSList *elem;
+	for(elem=from;elem!=NULL;elem=elem->next){
+		PayloadType *pt=(PayloadType*)elem->data;
+		if ((strcasecmp(type, payload_type_get_mime(pt)) == 0)
+			&& (rate == LINPHONE_FIND_PAYLOAD_IGNORE_RATE || rate==pt->clock_rate)
+			&& (channels == LINPHONE_FIND_PAYLOAD_IGNORE_CHANNELS || channels==pt->channels)) {
+			return pt;
+		}
+	}
+	return NULL;
+}
+
+static bool_t get_codec(LinphoneCore *lc, SalStreamType type, int index, PayloadType **ret){
 	char codeckey[50];
 	const char *mime,*fmtp;
 	int rate,channels,enabled;
@@ -1017,7 +1031,7 @@ static bool_t get_codec(LinphoneCore *lc, const char* type, int index, PayloadTy
 	LpConfig *config=lc->config;
 
 	*ret=NULL;
-	snprintf(codeckey,50,"%s_%i",type,index);
+	snprintf(codeckey,50,"%s_codec_%i",type==SalAudio ? "audio" : "video", index);
 	mime=lp_config_get_string(config,codeckey,"mime",NULL);
 	if (mime==NULL || strlen(mime)==0 ) return FALSE;
 
@@ -1025,85 +1039,52 @@ static bool_t get_codec(LinphoneCore *lc, const char* type, int index, PayloadTy
 	fmtp=lp_config_get_string(config,codeckey,"recv_fmtp",NULL);
 	channels=lp_config_get_int(config,codeckey,"channels",0);
 	enabled=lp_config_get_int(config,codeckey,"enabled",1);
-	pt=find_payload(lc->default_profile,mime,rate,channels,fmtp);
-	if (pt && enabled ) pt->flags|=PAYLOAD_TYPE_ENABLED;
-	//ms_message("Found codec %s/%i",pt->mime_type,pt->clock_rate);
-	if (pt==NULL) ms_warning("Ignoring codec config %s/%i with fmtp=%s because unsupported",
-				mime,rate,fmtp ? fmtp : "");
+	if (!ms_filter_codec_supported(mime)){
+		ms_warning("Codec %s/%i read from conf is not supported by mediastreamer2, ignored.",mime,rate);
+		return TRUE;
+	}
+	pt=find_payload(type==SalAudio ? lc->default_audio_codecs : lc->default_video_codecs,mime,rate,channels,fmtp);
+	if (!pt){
+		MSList **default_list=(type==SalAudio) ? &lc->default_audio_codecs :  &lc->default_video_codecs;
+		ms_warning("Codec %s/%i read from conf is not in the default list.",mime,rate);
+		pt=payload_type_new();
+		pt->type=(type==SalAudio) ? PAYLOAD_AUDIO_PACKETIZED :  PAYLOAD_VIDEO;
+		pt->mime_type=ortp_strdup(mime);
+		pt->clock_rate=rate;
+		pt->channels=channels;
+		payload_type_set_recv_fmtp(pt,fmtp);
+		*default_list=ms_list_append(*default_list, pt);
+	}
+	if (enabled ) pt->flags|=PAYLOAD_TYPE_ENABLED;
 	*ret=pt;
 	return TRUE;
 }
 
-#define RANK_END 10000
-
-typedef struct codec_desc{
-	const char *name;
-	int rate;
-}codec_desc_t;
-
-static codec_desc_t codec_pref_order[]={
-	{"opus", 48000},
-	{"SILK", 16000},
-	{"speex", 16000},
-	{"speex", 8000},
-	{"pcmu",8000},
-	{"pcma",8000},
-	{"VP8",90000},
-	{"H264",90000},
-	{"MP4V-ES",90000},
-	{NULL,0}
-};
-
-static int find_codec_rank(const char *mime, int clock_rate){
-	int i;
-
-#ifdef __arm__
-	/*hack for opus, that needs to be disabed by default on ARM single processor, otherwise there is no cpu left for video processing*/
-	if (strcasecmp(mime,"opus")==0){
-		if (ms_get_cpu_count()==1) return RANK_END;
-	}
-#endif
-	for(i=0;codec_pref_order[i].name!=NULL;++i){
-		if (strcasecmp(codec_pref_order[i].name,mime)==0 && clock_rate==codec_pref_order[i].rate)
-			return i;
-	}
-	return RANK_END;
-}
-
-static int codec_compare(const PayloadType *a, const PayloadType *b){
-	int ra,rb;
-	ra=find_codec_rank(a->mime_type,a->clock_rate);
-	rb=find_codec_rank(b->mime_type,b->clock_rate);
-	if (ra>rb) return 1;
-	if (ra<rb) return -1;
-	return 1;
-}
-
-static MSList *add_missing_codecs(LinphoneCore *lc, SalStreamType mtype, MSList *l){
-	int i;
-	for(i=0;i<RTP_PROFILE_MAX_PAYLOADS;++i){
-		PayloadType *pt=rtp_profile_get_payload(lc->default_profile,i);
-		if (pt){
-			if (mtype==SalVideo && pt->type!=PAYLOAD_VIDEO)
-				pt=NULL;
-			else if (mtype==SalAudio && (pt->type!=PAYLOAD_AUDIO_PACKETIZED
-				&& pt->type!=PAYLOAD_AUDIO_CONTINUOUS)){
-				pt=NULL;
-			}
-			if (pt && ms_filter_codec_supported(pt->mime_type)){
-				if (ms_list_find(l,pt)==NULL){
-					/*unranked codecs are disabled by default*/
-					if (find_codec_rank(pt->mime_type, pt->clock_rate)!=RANK_END){
-						payload_type_set_flag(pt,PAYLOAD_TYPE_ENABLED);
-					}
-					ms_message("Adding new codec %s/%i with fmtp %s",
-						pt->mime_type,pt->clock_rate,pt->recv_fmtp ? pt->recv_fmtp : "");
-					l=ms_list_insert_sorted(l,pt,(int (*)(const void *, const void *))codec_compare);
-				}
+/*this function merges the payload types from the codec default list with the list read from configuration file.
+ * If a new codec becomes supported in Liblinphone or if the list from configuration file is empty or incomplete, all the supported codecs are added
+ * automatically. This 'l' list is entirely destroyed and rewritten.*/
+static MSList *add_missing_codecs(const MSList *default_list, MSList *l){
+	const MSList *elem;
+	MSList *newlist;
+	
+	for(elem=default_list; elem!=NULL; elem=elem->next){
+		MSList *elem2=ms_list_find(l,elem->data);
+		if (!elem2){
+			PayloadType *pt=(PayloadType*)elem->data;
+			/*this codec from default list should be inserted in the list*/
+			if (!elem->prev){
+				l=ms_list_prepend(l,pt);
+			}else{
+				const MSList *after=ms_list_find(l,elem->prev->data);
+				l=ms_list_insert(l, after->next, pt);
 			}
+			ms_message("Supported codec %s/%i fmtp=%s automatically added to codec list.", pt->mime_type,
+				   pt->clock_rate, pt->recv_fmtp ? pt->recv_fmtp : "");
 		}
 	}
-	return l;
+	newlist=ms_list_copy_with_data(l,(void *(*)(void*))payload_type_clone);
+	ms_list_free(l);
+	return newlist;
 }
 
 static MSList *codec_append_if_new(MSList *l, PayloadType *pt){
@@ -1123,23 +1104,23 @@ static void codecs_config_read(LinphoneCore *lc)
 	PayloadType *pt;
 	MSList *audio_codecs=NULL;
 	MSList *video_codecs=NULL;
-	for (i=0;get_codec(lc,"audio_codec",i,&pt);i++){
+	
+	lc->codecs_conf.dyn_pt=96;
+	lc->codecs_conf.telephone_event_pt=lp_config_get_int(lc->config,"misc","telephone_event_pt",101);
+	
+	for (i=0;get_codec(lc,SalAudio,i,&pt);i++){
 		if (pt){
-			if (!ms_filter_codec_supported(pt->mime_type)){
-				ms_warning("Codec %s is not supported by mediastreamer2, removed.",pt->mime_type);
-			}else audio_codecs=codec_append_if_new(audio_codecs,pt);
+			audio_codecs=codec_append_if_new(audio_codecs, pt);
 		}
 	}
-	audio_codecs=add_missing_codecs(lc,SalAudio,audio_codecs);
+	audio_codecs=add_missing_codecs(lc->default_audio_codecs,audio_codecs);
 
-	for (i=0;get_codec(lc,"video_codec",i,&pt);i++){
+	for (i=0;get_codec(lc,SalVideo,i,&pt);i++){
 		if (pt){
-			if (!ms_filter_codec_supported(pt->mime_type)){
-				ms_warning("Codec %s is not supported by mediastreamer2, removed.",pt->mime_type);
-			}else video_codecs=codec_append_if_new(video_codecs,(void *)pt);
+			video_codecs=codec_append_if_new(video_codecs, pt);
 		}
 	}
-	video_codecs=add_missing_codecs(lc,SalVideo,video_codecs);
+	video_codecs=add_missing_codecs(lc->default_video_codecs,video_codecs);
 	linphone_core_set_audio_codecs(lc,audio_codecs);
 	linphone_core_set_video_codecs(lc,video_codecs);
 	linphone_core_update_allocated_audio_bandwidth(lc);
@@ -1412,60 +1393,45 @@ const char * linphone_core_get_version(void){
 	return liblinphone_version;
 }
 
-static void linphone_core_assign_payload_type(LinphoneCore *lc, PayloadType *const_pt, int number, const char *recv_fmtp){
-	PayloadType *pt;
-
-	pt=payload_type_clone(const_pt);
-	if (number==-1){
-		/*look for a free number */
-		MSList *elem;
-		int i;
-		for(i=lc->dyn_pt;i<RTP_PROFILE_MAX_PAYLOADS;++i){
-			bool_t already_assigned=FALSE;
-			for(elem=lc->payload_types;elem!=NULL;elem=elem->next){
-				PayloadType *it=(PayloadType*)elem->data;
-				if (payload_type_get_number(it)==i){
-					already_assigned=TRUE;
-					break;
-				}
-			}
-			if (!already_assigned){
-				number=i;
-				lc->dyn_pt=i+1;
-				break;
-			}
-		}
-		if (number==-1){
-			ms_fatal("FIXME: too many codecs, no more free numbers.");
-		}
+static void linphone_core_register_payload_type(LinphoneCore *lc, const PayloadType *const_pt, const char *recv_fmtp, bool_t enabled){
+	MSList **codec_list=const_pt->type==PAYLOAD_VIDEO ? &lc->default_video_codecs : &lc->default_audio_codecs;
+	if (ms_filter_codec_supported(const_pt->mime_type)){
+		PayloadType *pt=payload_type_clone(const_pt);
+		int number=-1;
+		payload_type_set_enable(pt,enabled);
+		if (recv_fmtp!=NULL) payload_type_set_recv_fmtp(pt,recv_fmtp);
+		/*Set a number to the payload type from the statically defined (RFC3551) profile, if not static, -1 is returned
+		 and the payload type number will be determined dynamically later, at call time.*/
+		payload_type_set_number(pt,
+			(number=rtp_profile_find_payload_number(&av_profile, pt->mime_type, pt->clock_rate, pt->channels))
+		); 
+		ms_message("Codec %s/%i fmtp=[%s] number=%i, enabled=%i) added to default capabilities.", pt->mime_type, pt->clock_rate, 
+			   pt->recv_fmtp ? pt->recv_fmtp : "", number, (int)payload_type_enabled(pt));
+		*codec_list=ms_list_append(*codec_list,pt);
 	}
-	ms_message("assigning %s/%i payload type number %i",pt->mime_type,pt->clock_rate,number);
-	payload_type_set_number(pt,number);
-	if (recv_fmtp!=NULL) payload_type_set_recv_fmtp(pt,recv_fmtp);
-	rtp_profile_set_payload(lc->default_profile,number,pt);
-	lc->payload_types=ms_list_append(lc->payload_types,pt);
 }
 
-static void linphone_core_handle_static_payloads(LinphoneCore *lc){
+static void linphone_core_register_static_payloads(LinphoneCore *lc){
 	RtpProfile *prof=&av_profile;
 	int i;
 	for(i=0;i<RTP_PROFILE_MAX_PAYLOADS;++i){
 		PayloadType *pt=rtp_profile_get_payload(prof,i);
 		if (pt){
-			// insert static payload only if no profile exists
-			if (rtp_profile_get_payload(lc->default_profile,i) == NULL){
-				linphone_core_assign_payload_type(lc,pt,i,NULL);
+#ifndef VIDEO_ENABLED
+			if (pt->type==PAYLOAD_VIDEO) continue;
+#endif
+			if (find_payload_type_from_list(
+				pt->mime_type, pt->clock_rate, pt->type!=PAYLOAD_VIDEO ? pt->channels : LINPHONE_FIND_PAYLOAD_IGNORE_CHANNELS,
+				pt->type==PAYLOAD_VIDEO ? lc->default_video_codecs : lc->default_audio_codecs)==NULL){
+				linphone_core_register_payload_type(lc,pt,NULL,FALSE);
 			}
 		}
 	}
 }
 
 static void linphone_core_free_payload_types(LinphoneCore *lc){
-	rtp_profile_clear_all(lc->default_profile);
-	rtp_profile_destroy(lc->default_profile);
-	ms_list_for_each(lc->payload_types,(void (*)(void*))payload_type_destroy);
-	ms_list_free(lc->payload_types);
-	lc->payload_types=NULL;
+	ms_list_free_with_data(lc->default_audio_codecs, (void (*)(void*))payload_type_destroy);
+	ms_list_free_with_data(lc->default_video_codecs, (void (*)(void*))payload_type_destroy);
 }
 
 void linphone_core_set_state(LinphoneCore *lc, LinphoneGlobalState gstate, const char *message){
@@ -1541,10 +1507,73 @@ static void linphone_core_deactivate_log_serialization_if_needed(void) {
 	}
 }
 
-static void linphone_core_init(LinphoneCore * lc, const LinphoneCoreVTable *vtable, LpConfig *config, void * userdata)
-{
-	const char *remote_provisioning_uri = NULL;
+static void linphone_core_register_default_codecs(LinphoneCore *lc){
 	const char *aac_fmtp162248, *aac_fmtp3244;
+	bool_t opus_enabled=TRUE;
+	/*default enabled audio codecs, in order of preference*/
+#ifdef __arm__
+	/*hack for opus, that needs to be disabed by default on ARM single processor, otherwise there is no cpu left for video processing*/
+	if (ms_get_cpu_count()==1) opus_enabled=FALSE;
+#endif
+	linphone_core_register_payload_type(lc,&payload_type_opus,"useinbandfec=1; stereo=0; sprop-stereo=0",opus_enabled);
+	linphone_core_register_payload_type(lc,&payload_type_silk_wb,NULL,TRUE);
+	linphone_core_register_payload_type(lc,&payload_type_speex_wb,"vbr=on",TRUE);
+	linphone_core_register_payload_type(lc,&payload_type_speex_nb,"vbr=on",TRUE);
+	linphone_core_register_payload_type(lc,&payload_type_pcmu8000,NULL,TRUE);
+	linphone_core_register_payload_type(lc,&payload_type_pcma8000,NULL,TRUE);
+	
+	/*other audio codecs, not enabled by default, in order of preference*/
+	linphone_core_register_payload_type(lc,&payload_type_gsm,NULL,FALSE);
+	linphone_core_register_payload_type(lc,&payload_type_g722,NULL,FALSE);
+	linphone_core_register_payload_type(lc,&payload_type_ilbc,"mode=30",FALSE);
+	linphone_core_register_payload_type(lc,&payload_type_amr,"octet-align=1",FALSE);
+	linphone_core_register_payload_type(lc,&payload_type_amrwb,"octet-align=1",FALSE);
+	linphone_core_register_payload_type(lc,&payload_type_g729,"annexb=no",FALSE);
+	/* For AAC, we use a config value to determine if we ought to support SBR. Since it is not offically supported
+	 * for the mpeg4-generic mime type, setting this flag to 1 will break compatibility with other clients. */
+	if( lp_config_get_int(lc->config, "misc", "aac_use_sbr", FALSE) ) {
+		ms_message("Using SBR for AAC");
+		aac_fmtp162248 = "config=F8EE2000; constantDuration=512; indexDeltaLength=3; indexLength=3; mode=AAC-hbr; profile-level-id=76; sizeLength=13; streamType=5; SBR-enabled=1";
+		aac_fmtp3244   = "config=F8E82000; constantDuration=512; indexDeltaLength=3; indexLength=3; mode=AAC-hbr; profile-level-id=76; sizeLength=13; streamType=5; SBR-enabled=1";
+	} else {
+		aac_fmtp162248 = "config=F8EE2000; constantDuration=512; indexDeltaLength=3; indexLength=3; mode=AAC-hbr; profile-level-id=76; sizeLength=13; streamType=5";
+		aac_fmtp3244   = "config=F8E82000; constantDuration=512; indexDeltaLength=3; indexLength=3; mode=AAC-hbr; profile-level-id=76; sizeLength=13; streamType=5";
+	}
+	linphone_core_register_payload_type(lc,&payload_type_aaceld_16k,aac_fmtp162248,FALSE);
+	linphone_core_register_payload_type(lc,&payload_type_aaceld_22k,aac_fmtp162248,FALSE);
+	linphone_core_register_payload_type(lc,&payload_type_aaceld_32k,aac_fmtp3244,FALSE);
+	linphone_core_register_payload_type(lc,&payload_type_aaceld_44k,aac_fmtp3244,FALSE);
+	linphone_core_register_payload_type(lc,&payload_type_aaceld_48k,aac_fmtp162248,FALSE);
+	linphone_core_register_payload_type(lc,&payload_type_isac,NULL,FALSE);
+	linphone_core_register_payload_type(lc,&payload_type_speex_uwb,"vbr=on",FALSE);
+	linphone_core_register_payload_type(lc,&payload_type_silk_nb,NULL,FALSE);
+	linphone_core_register_payload_type(lc,&payload_type_silk_mb,NULL,FALSE);
+	linphone_core_register_payload_type(lc,&payload_type_silk_swb,NULL,FALSE);
+	linphone_core_register_payload_type(lc,&payload_type_g726_16,NULL,FALSE);
+	linphone_core_register_payload_type(lc,&payload_type_g726_24,NULL,FALSE);
+	linphone_core_register_payload_type(lc,&payload_type_g726_32,NULL,FALSE);
+	linphone_core_register_payload_type(lc,&payload_type_g726_40,NULL,FALSE);
+	linphone_core_register_payload_type(lc,&payload_type_aal2_g726_16,NULL,FALSE);
+	linphone_core_register_payload_type(lc,&payload_type_aal2_g726_24,NULL,FALSE);
+	linphone_core_register_payload_type(lc,&payload_type_aal2_g726_32,NULL,FALSE);
+	linphone_core_register_payload_type(lc,&payload_type_aal2_g726_40,NULL,FALSE);
+	
+	
+
+#ifdef VIDEO_ENABLED
+	/*default enabled video codecs, in order of preference*/
+	linphone_core_register_payload_type(lc,&payload_type_vp8,NULL,TRUE);
+	linphone_core_register_payload_type(lc,&payload_type_h264,"profile-level-id=42801F",TRUE);
+	linphone_core_register_payload_type(lc,&payload_type_mp4v,"profile-level-id=3",TRUE);
+	linphone_core_register_payload_type(lc,&payload_type_h263_1998,"CIF=1;QCIF=1",FALSE);
+	linphone_core_register_payload_type(lc,&payload_type_h263,NULL,FALSE);
+#endif
+	/*register all static payload types declared in av_profile of oRTP, if not already declared above*/
+	linphone_core_register_static_payloads(lc);
+}
+
+static void linphone_core_init(LinphoneCore * lc, const LinphoneCoreVTable *vtable, LpConfig *config, void * userdata){
+	const char *remote_provisioning_uri = NULL;
 	LinphoneCoreVTable* local_vtable= linphone_core_v_table_new();
 	ms_message("Initializing LinphoneCore %s", linphone_core_get_version());
 
@@ -1558,83 +1587,10 @@ static void linphone_core_init(LinphoneCore * lc, const LinphoneCoreVTable *vtab
 	linphone_core_set_state(lc,LinphoneGlobalStartup,"Starting up");
 	ortp_init();
 	linphone_core_activate_log_serialization_if_needed();
-	lc->dyn_pt=96;
-	lc->default_profile=rtp_profile_new("default profile");
-	linphone_core_assign_payload_type(lc,&payload_type_pcmu8000,0,NULL);
-	linphone_core_assign_payload_type(lc,&payload_type_gsm,3,NULL);
-	linphone_core_assign_payload_type(lc,&payload_type_pcma8000,8,NULL);
-	linphone_core_assign_payload_type(lc,&payload_type_speex_nb,110,"vbr=on");
-	linphone_core_assign_payload_type(lc,&payload_type_speex_wb,111,"vbr=on");
-	linphone_core_assign_payload_type(lc,&payload_type_speex_uwb,112,"vbr=on");
-	linphone_core_assign_payload_type(lc,&payload_type_telephone_event,101,"0-15");
-	linphone_core_assign_payload_type(lc,&payload_type_g722,9,NULL);
-
-#ifdef ENABLE_NONSTANDARD_GSM
-	{
-		PayloadType *pt;
-		pt=payload_type_clone(&payload_type_gsm);
-		pt->clock_rate=11025;
-		linphone_core_assign_payload_type(lc,pt,-1,NULL);
-		pt->clock_rate=22050;
-		linphone_core_assign_payload_type(lc,pt,-1,NULL);
-		payload_type_destroy(pt);
-	}
-#endif
-
-#ifdef VIDEO_ENABLED
-
-	linphone_core_assign_payload_type(lc,&payload_type_h263,34,NULL);
-	linphone_core_assign_payload_type(lc,&payload_type_h263_1998,98,"CIF=1;QCIF=1");
-	linphone_core_assign_payload_type(lc,&payload_type_mp4v,99,"profile-level-id=3");
-	linphone_core_assign_payload_type(lc,&payload_type_h264,102,"profile-level-id=42801F");
-	linphone_core_assign_payload_type(lc,&payload_type_vp8,103,NULL);
-
-	/* linphone_core_assign_payload_type(lc,&payload_type_theora,97,NULL); commented out to free 1 slot */
-	/* linphone_core_assign_payload_type(lc,&payload_type_x_snow,-1,NULL); commented out to free 1 slot */
-	/* due to limited space in SDP, we have to disable this h264 line which is normally no more necessary */
-	/* linphone_core_assign_payload_type(&payload_type_h264,-1,"packetization-mode=1;profile-level-id=428014");*/
-#endif
-
-	/* For AAC, we use a config value to determine if we ought to support SBR. Since it is not offically supported
-	 * for the mpeg4-generic mime type, setting this flag to 1 will break compatibility with other clients. */
-	if( lp_config_get_int(lc->config, "misc", "aac_use_sbr", FALSE) ) {
-		ms_message("Using SBR for AAC");
-		aac_fmtp162248 = "config=F8EE2000; constantDuration=512; indexDeltaLength=3; indexLength=3; mode=AAC-hbr; profile-level-id=76; sizeLength=13; streamType=5; SBR-enabled=1";
-		aac_fmtp3244   = "config=F8E82000; constantDuration=512; indexDeltaLength=3; indexLength=3; mode=AAC-hbr; profile-level-id=76; sizeLength=13; streamType=5; SBR-enabled=1";
-	} else {
-		aac_fmtp162248 = "config=F8EE2000; constantDuration=512; indexDeltaLength=3; indexLength=3; mode=AAC-hbr; profile-level-id=76; sizeLength=13; streamType=5";
-		aac_fmtp3244   = "config=F8E82000; constantDuration=512; indexDeltaLength=3; indexLength=3; mode=AAC-hbr; profile-level-id=76; sizeLength=13; streamType=5";
-	}
-
-
-	/*add all payload type for which we don't care about the number */
-	linphone_core_assign_payload_type(lc,&payload_type_ilbc,-1,"mode=30");
-	linphone_core_assign_payload_type(lc,&payload_type_amr,-1,"octet-align=1");
-	linphone_core_assign_payload_type(lc,&payload_type_amrwb,-1,"octet-align=1");
-	/* linphone_core_assign_payload_type(lc,&payload_type_lpc1015,-1,NULL); commented out to free 1 slot */
-	linphone_core_assign_payload_type(lc,&payload_type_g726_16,-1,NULL);
-	linphone_core_assign_payload_type(lc,&payload_type_g726_24,-1,NULL);
-	linphone_core_assign_payload_type(lc,&payload_type_g726_32,-1,NULL);
-	linphone_core_assign_payload_type(lc,&payload_type_g726_40,-1,NULL);
-	linphone_core_assign_payload_type(lc,&payload_type_aal2_g726_16,-1,NULL);
-	linphone_core_assign_payload_type(lc,&payload_type_aal2_g726_24,-1,NULL);
-	linphone_core_assign_payload_type(lc,&payload_type_aal2_g726_32,-1,NULL);
-	linphone_core_assign_payload_type(lc,&payload_type_aal2_g726_40,-1,NULL);
-	linphone_core_assign_payload_type(lc,&payload_type_silk_nb,-1,NULL);
-	linphone_core_assign_payload_type(lc,&payload_type_silk_mb,-1,NULL);
-	linphone_core_assign_payload_type(lc,&payload_type_silk_wb,-1,NULL);
-	linphone_core_assign_payload_type(lc,&payload_type_silk_swb,-1,NULL);
-	linphone_core_assign_payload_type(lc,&payload_type_g729,18,"annexb=no");
-	linphone_core_assign_payload_type(lc,&payload_type_aaceld_16k,-1,aac_fmtp162248);
-	linphone_core_assign_payload_type(lc,&payload_type_aaceld_22k,-1,aac_fmtp162248);
-	linphone_core_assign_payload_type(lc,&payload_type_aaceld_32k,-1,aac_fmtp3244);
-	linphone_core_assign_payload_type(lc,&payload_type_aaceld_44k,-1,aac_fmtp3244);
-	linphone_core_assign_payload_type(lc,&payload_type_aaceld_48k,-1,aac_fmtp162248);
-	linphone_core_assign_payload_type(lc,&payload_type_opus,-1,"useinbandfec=1; stereo=0; sprop-stereo=0");
-	linphone_core_assign_payload_type(lc,&payload_type_isac,-1,NULL);
-	linphone_core_handle_static_payloads(lc);
-
+	
 	ms_init();
+	
+	linphone_core_register_default_codecs(lc);
 	/* create a mediastreamer2 event queue and set it as global */
 	/* This allows to run event's callback in linphone_core_iterate() */
 	lc->msevq=ms_event_queue_new();
@@ -1841,8 +1797,7 @@ LinphoneAddress *linphone_core_get_primary_contact_parsed(LinphoneCore *lc){
  * The list is taken by the LinphoneCore thus the application should not free it.
  * This list is made of struct PayloadType describing the codec parameters.
 **/
-int linphone_core_set_audio_codecs(LinphoneCore *lc, MSList *codecs)
-{
+int linphone_core_set_audio_codecs(LinphoneCore *lc, MSList *codecs){
 	if (lc->codecs_conf.audio_codecs!=NULL) ms_list_free(lc->codecs_conf.audio_codecs);
 	lc->codecs_conf.audio_codecs=codecs;
 	_linphone_core_codec_config_write(lc);
@@ -1860,8 +1815,7 @@ int linphone_core_set_audio_codecs(LinphoneCore *lc, MSList *codecs)
  * The list is taken by the LinphoneCore thus the application should not free it.
  * This list is made of struct PayloadType describing the codec parameters.
 **/
-int linphone_core_set_video_codecs(LinphoneCore *lc, MSList *codecs)
-{
+int linphone_core_set_video_codecs(LinphoneCore *lc, MSList *codecs){
 	if (lc->codecs_conf.video_codecs!=NULL) ms_list_free(lc->codecs_conf.video_codecs);
 	lc->codecs_conf.video_codecs=codecs;
 	_linphone_core_codec_config_write(lc);
@@ -6212,8 +6166,8 @@ void _linphone_core_codec_config_write(LinphoneCore *lc){
 static void codecs_config_uninit(LinphoneCore *lc)
 {
 	_linphone_core_codec_config_write(lc);
-	ms_list_free(lc->codecs_conf.audio_codecs);
-	ms_list_free(lc->codecs_conf.video_codecs);
+	ms_list_free_with_data(lc->codecs_conf.audio_codecs, (void (*)(void*))payload_type_destroy);
+	ms_list_free_with_data(lc->codecs_conf.video_codecs, (void (*)(void*))payload_type_destroy);
 }
 
 void ui_config_uninit(LinphoneCore* lc)
@@ -6519,20 +6473,6 @@ const char *linphone_core_get_remote_ringback_tone(const LinphoneCore *lc){
 	return lc->sound_conf.ringback_tone;
 }
 
-static PayloadType* find_payload_type_from_list(const char* type, int rate, int channels, const MSList* from) {
-	const MSList *elem;
-	for(elem=from;elem!=NULL;elem=elem->next){
-		PayloadType *pt=(PayloadType*)elem->data;
-		if ((strcasecmp((char*)type, payload_type_get_mime(pt)) == 0)
-			&& (rate == LINPHONE_FIND_PAYLOAD_IGNORE_RATE || rate==pt->clock_rate)
-			&& (channels == LINPHONE_FIND_PAYLOAD_IGNORE_CHANNELS || channels==pt->channels)) {
-			return pt;
-		}
-	}
-	return NULL;
-}
-
-
 LinphonePayloadType* linphone_core_find_payload_type(LinphoneCore* lc, const char* type, int rate, int channels) {
 	LinphonePayloadType* result = find_payload_type_from_list(type, rate, channels, linphone_core_get_audio_codecs(lc));
 	if (result)  {
diff --git a/coreapi/linphonecore.h b/coreapi/linphonecore.h
index c8a259f25..1e72fcd0a 100644
--- a/coreapi/linphonecore.h
+++ b/coreapi/linphonecore.h
@@ -2345,8 +2345,19 @@ LINPHONE_PUBLIC	int linphone_core_enable_payload_type(LinphoneCore *lc, Linphone
  */
 LINPHONE_PUBLIC	LinphonePayloadType* linphone_core_find_payload_type(LinphoneCore* lc, const char* type, int rate, int channels) ;
 
+/**
+ * @ingroup media_parameters
+ * Returns the payload type number assigned for this codec.
+**/
 LINPHONE_PUBLIC	int linphone_core_get_payload_type_number(LinphoneCore *lc, const PayloadType *pt);
 
+/**
+ * @ingroup media_parameters
+ * Force a number for a payload type. The LinphoneCore does payload type number assignment automatically. THis function is to be used mainly for tests, in order
+ * to override the automatic assignment mechanism.
+**/
+LINPHONE_PUBLIC void linphone_core_set_payload_type_number(LinphoneCore *lc, PayloadType *pt, int number);
+
 LINPHONE_PUBLIC	const char *linphone_core_get_payload_type_description(LinphoneCore *lc, PayloadType *pt);
 
 LINPHONE_PUBLIC	bool_t linphone_core_check_payload_type_usability(LinphoneCore *lc, const PayloadType *pt);
diff --git a/coreapi/misc.c b/coreapi/misc.c
index 59244d3de..d88c80cd5 100644
--- a/coreapi/misc.c
+++ b/coreapi/misc.c
@@ -59,15 +59,6 @@ Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 #define RTP_HDR_SZ 12
 #define IP4_HDR_SZ 20   /*20 is the minimum, but there may be some options*/
 
-static void payload_type_set_enable(PayloadType *pt,int value)
-{
-	if ((value)!=0) payload_type_set_flag(pt,PAYLOAD_TYPE_ENABLED); \
-	else payload_type_unset_flag(pt,PAYLOAD_TYPE_ENABLED);
-}
-
-static bool_t payload_type_enabled(const PayloadType *pt) {
-	return (((pt)->flags & PAYLOAD_TYPE_ENABLED)!=0);
-}
 
 bool_t linphone_core_payload_type_enabled(LinphoneCore *lc, const LinphonePayloadType *pt){
 	if (ms_list_find(lc->codecs_conf.audio_codecs, (PayloadType*) pt) || ms_list_find(lc->codecs_conf.video_codecs, (PayloadType*)pt)){
@@ -97,6 +88,10 @@ int linphone_core_get_payload_type_number(LinphoneCore *lc, const PayloadType *p
 	return payload_type_get_number(pt);
 }
 
+void linphone_core_set_payload_type_number(LinphoneCore *lc, PayloadType *pt, int number){
+	payload_type_set_number(pt,number);
+}
+
 const char *linphone_core_get_payload_type_description(LinphoneCore *lc, PayloadType *pt){
 	if (ms_filter_codec_supported(pt->mime_type)){
 		MSFilterDesc *desc=ms_filter_get_encoder(pt->mime_type);
diff --git a/coreapi/offeranswer.c b/coreapi/offeranswer.c
index d7d2e6e84..b9ece30d8 100644
--- a/coreapi/offeranswer.c
+++ b/coreapi/offeranswer.c
@@ -110,6 +110,7 @@ static MSList *match_payloads(const MSList *local, const MSList *remote, bool_t
 			res=ms_list_append(res,newp);
 			/* we should use the remote numbering even when parsing a response */
 			payload_type_set_number(newp,remote_number);
+			payload_type_set_flag(newp, PAYLOAD_TYPE_FROZEN_NUMBER);
 			if (reading_response && remote_number!=local_number){
 				ms_warning("For payload type %s, proposed number was %i but the remote phone answered %i",
 						  newp->mime_type, local_number, remote_number);
@@ -120,6 +121,7 @@ static MSList *match_payloads(const MSList *local, const MSList *remote, bool_t
 				*/
 				newp=payload_type_clone(newp);
 				payload_type_set_number(newp,local_number);
+				payload_type_set_flag(newp, PAYLOAD_TYPE_FROZEN_NUMBER);
 				res=ms_list_append(res,newp);
 			}
 		}else{
@@ -143,7 +145,8 @@ static MSList *match_payloads(const MSList *local, const MSList *remote, bool_t
 			if (!found){
 				ms_message("Adding %s/%i for compatibility, just in case.",p1->mime_type,p1->clock_rate);
 				p1=payload_type_clone(p1);
-				p1->flags|=PAYLOAD_TYPE_FLAG_CAN_RECV;
+				payload_type_set_flag(p1, PAYLOAD_TYPE_FLAG_CAN_RECV);
+				payload_type_set_flag(p1, PAYLOAD_TYPE_FROZEN_NUMBER);
 				res=ms_list_append(res,p1);
 			}
 		}
diff --git a/coreapi/private.h b/coreapi/private.h
index 55f1f1034..68a0e6354 100644
--- a/coreapi/private.h
+++ b/coreapi/private.h
@@ -365,6 +365,7 @@ static MS2_INLINE void set_string(char **dest, const char *src){
 
 #define PAYLOAD_TYPE_ENABLED	PAYLOAD_TYPE_USER_FLAG_0
 #define PAYLOAD_TYPE_BITRATE_OVERRIDE PAYLOAD_TYPE_USER_FLAG_3
+#define PAYLOAD_TYPE_FROZEN_NUMBER	PAYLOAD_TYPE_USER_FLAG_4
 
 void linphone_process_authentication(LinphoneCore* lc, SalOp *op);
 void linphone_authentication_ok(LinphoneCore *lc, SalOp *op);
@@ -643,7 +644,9 @@ typedef struct sound_config
 typedef struct codecs_config
 {
 	MSList *audio_codecs;  /* list of audio codecs in order of preference*/
-	MSList *video_codecs;	/* for later use*/
+	MSList *video_codecs;
+	int dyn_pt;
+	int telephone_event_pt;
 }codecs_config_t;
 
 typedef struct video_config{
@@ -710,7 +713,8 @@ struct _LinphoneCore
 	Sal *sal;
 	LinphoneGlobalState state;
 	struct _LpConfig *config;
-	RtpProfile *default_profile;
+	MSList *default_audio_codecs;
+	MSList *default_video_codecs;
 	net_config_t net_conf;
 	sip_config_t sip_conf;
 	rtp_config_t rtp_conf;
@@ -719,8 +723,6 @@ struct _LinphoneCore
 	codecs_config_t codecs_conf;
 	ui_config_t ui_conf;
 	autoreplier_config_t autoreplier_conf;
-	MSList *payload_types;
-	int dyn_pt;
 	LinphoneProxyConfig *default_proxy;
 	MSList *friends;
 	MSList *auth_info;
@@ -1014,6 +1016,18 @@ static MS2_INLINE const LinphoneErrorInfo *linphone_error_info_from_sal_op(const
 	return (const LinphoneErrorInfo*)sal_op_get_error_info(op);
 }
 
+static MS2_INLINE void payload_type_set_enable(PayloadType *pt,int value)
+{
+	if ((value)!=0) payload_type_set_flag(pt,PAYLOAD_TYPE_ENABLED); \
+	else payload_type_unset_flag(pt,PAYLOAD_TYPE_ENABLED);
+}
+
+static MS2_INLINE bool_t payload_type_enabled(const PayloadType *pt) {
+	return (((pt)->flags & PAYLOAD_TYPE_ENABLED)!=0);
+}
+
+bool_t is_payload_type_number_available(const MSList *l, int number, const PayloadType *ignore);
+
 const MSCryptoSuite * linphone_core_get_srtp_crypto_suites(LinphoneCore *lc);
 
 /** Belle Sip-based objects need unique ids
diff --git a/coreapi/quality_reporting.c b/coreapi/quality_reporting.c
index bb1d443bf..e22f7229c 100644
--- a/coreapi/quality_reporting.c
+++ b/coreapi/quality_reporting.c
@@ -332,6 +332,7 @@ static int send_report(LinphoneCall* call, reporting_session_report_t * report,
 	}
 
 	linphone_content_set_buffer(content, buffer, strlen(buffer));
+	ms_free(buffer);
 
 	if (call->log->reporting.on_report_sent != NULL){
 		call->log->reporting.on_report_sent(
diff --git a/coreapi/sal.c b/coreapi/sal.c
index b8395c897..1577f95f6 100644
--- a/coreapi/sal.c
+++ b/coreapi/sal.c
@@ -62,9 +62,10 @@ SalMediaDescription *sal_media_description_new(){
 static void sal_media_description_destroy(SalMediaDescription *md){
 	int i;
 	for(i=0;i<SAL_MEDIA_DESCRIPTION_MAX_STREAMS;i++){
-		ms_list_for_each(md->streams[i].payloads,(void (*)(void *))payload_type_destroy);
-		ms_list_free(md->streams[i].payloads);
+		ms_list_free_with_data(md->streams[i].payloads,(void (*)(void *))payload_type_destroy);
+		ms_list_free_with_data(md->streams[i].already_assigned_payloads,(void (*)(void *))payload_type_destroy);
 		md->streams[i].payloads=NULL;
+		md->streams[i].already_assigned_payloads=NULL;
 	}
 	ms_free(md);
 }
diff --git a/include/sal/sal.h b/include/sal/sal.h
index c44317c88..42f2d6da8 100644
--- a/include/sal/sal.h
+++ b/include/sal/sal.h
@@ -196,7 +196,8 @@ typedef struct SalStreamDescription{
 	char rtcp_addr[64];
 	int rtp_port;
 	int rtcp_port;
-	MSList *payloads; //<list of PayloadType
+	MSList *payloads; /*<list of PayloadType */
+	MSList *already_assigned_payloads; /*<list of PayloadType offered in the past, used for correct allocation of payload type numbers*/
 	int bandwidth;
 	int ptime;
 	SalStreamDir dir;
diff --git a/mediastreamer2 b/mediastreamer2
index 5662b24bc..7d2a30214 160000
--- a/mediastreamer2
+++ b/mediastreamer2
@@ -1 +1 @@
-Subproject commit 5662b24bc9ddd186daae74555b05b42bfedd763d
+Subproject commit 7d2a30214b8010224eed26bc1f239907618b9674
diff --git a/oRTP b/oRTP
index 0ad89f5e1..e5470e271 160000
--- a/oRTP
+++ b/oRTP
@@ -1 +1 @@
-Subproject commit 0ad89f5e106d9f9a4a1d0608101d26b9a10be8b7
+Subproject commit e5470e271d5be74f425db9221cd35a60ce4cf52e
diff --git a/tester/Makefile.am b/tester/Makefile.am
index d296841ad..6c5ba79bc 100644
--- a/tester/Makefile.am
+++ b/tester/Makefile.am
@@ -26,7 +26,8 @@ liblinphonetester_la_SOURCES = tester.c \
 				transport_tester.c \
 				player_tester.c \
 				dtmf_tester.c \
-				accountmanager.c
+				accountmanager.c \
+				offeranswer_tester.c
 
 liblinphonetester_la_LDFLAGS= -no-undefined
 liblinphonetester_la_LIBADD= ../coreapi/liblinphone.la $(CUNIT_LIBS)
diff --git a/tester/accountmanager.c b/tester/accountmanager.c
index 97cf8803b..2236b2039 100644
--- a/tester/accountmanager.c
+++ b/tester/accountmanager.c
@@ -77,6 +77,7 @@ void account_manager_destroy(void){
 		ms_free(the_am);
 	}
 	the_am=NULL;
+	ms_message("Test account manager destroyed.");
 }
 
 Account *account_manager_get_account(AccountManager *m, const LinphoneAddress *identity){
@@ -211,10 +212,6 @@ void linphone_core_manager_check_accounts(LinphoneCoreManager *m){
 
 	for(it=linphone_core_get_proxy_config_list(m->lc);it!=NULL;it=it->next){
 		LinphoneProxyConfig *cfg=(LinphoneProxyConfig *)it->data;
-		LinphoneAddress *modified_identity=account_manager_check_account(am,cfg);
-		if (m->identity){
-			linphone_address_unref(m->identity);
-		}
-		m->identity=linphone_address_ref(modified_identity);
+		account_manager_check_account(am,cfg);
 	}
 }
diff --git a/tester/call_tester.c b/tester/call_tester.c
index d608e9723..51cd2d550 100644
--- a/tester/call_tester.c
+++ b/tester/call_tester.c
@@ -34,7 +34,6 @@
 
 static void srtp_call(void);
 static void call_base(LinphoneMediaEncryption mode, bool_t enable_video,bool_t enable_relay,LinphoneFirewallPolicy policy);
-static void disable_all_audio_codecs_except_one(LinphoneCore *lc, const char *mime, int rate);
 static char *create_filepath(const char *dir, const char *filename, const char *ext);
 
 // prototype definition for call_recording()
@@ -727,7 +726,7 @@ static void cancelled_call(void) {
 	linphone_core_manager_destroy(pauline);
 }
 
-static void disable_all_audio_codecs_except_one(LinphoneCore *lc, const char *mime, int rate){
+void disable_all_audio_codecs_except_one(LinphoneCore *lc, const char *mime, int rate){
 	const MSList *elem=linphone_core_get_audio_codecs(lc);
 	PayloadType *pt;
 
@@ -754,40 +753,6 @@ static void disable_all_video_codecs_except_one(LinphoneCore *lc, const char *mi
 }
 #endif
 
-static void call_failed_because_of_codecs(void) {
-	int begin,leaked_objects;
-
-	belle_sip_object_enable_leak_detector(TRUE);
-	begin=belle_sip_object_get_object_count();
-
-	{
-		LinphoneCoreManager* marie = linphone_core_manager_new( "marie_rc");
-		LinphoneCoreManager* pauline = linphone_core_manager_new( "pauline_rc");
-		LinphoneCall* out_call;
-
-		disable_all_audio_codecs_except_one(marie->lc,"pcmu",-1);
-		disable_all_audio_codecs_except_one(pauline->lc,"pcma",-1);
-		out_call = linphone_core_invite_address(pauline->lc,marie->identity);
-		linphone_call_ref(out_call);
-		CU_ASSERT_TRUE(wait_for(pauline->lc,marie->lc,&pauline->stat.number_of_LinphoneCallOutgoingInit,1));
-
-		/*flexisip will retain the 488 until the "urgent reply" timeout (I.E 5s) arrives.*/
-		CU_ASSERT_TRUE(wait_for_until(pauline->lc,marie->lc,&pauline->stat.number_of_LinphoneCallError,1,7000));
-		CU_ASSERT_EQUAL(linphone_call_get_reason(out_call),LinphoneReasonNotAcceptable);
-		CU_ASSERT_EQUAL(marie->stat.number_of_LinphoneCallIncomingReceived,0);
-		CU_ASSERT_EQUAL(marie->stat.number_of_LinphoneCallReleased,0);
-
-		linphone_call_unref(out_call);
-		linphone_core_manager_destroy(marie);
-		linphone_core_manager_destroy(pauline);
-	}
-	leaked_objects=belle_sip_object_get_object_count()-begin;
-	CU_ASSERT_TRUE(leaked_objects==0);
-	if (leaked_objects>0){
-		belle_sip_object_dump_active_objects();
-	}
-}
-
 static void call_with_dns_time_out(void) {
 	LinphoneCoreManager* marie = linphone_core_manager_new2( "empty_rc", FALSE);
 	LCSipTransports transport = {9773,0,0,0};
@@ -3036,115 +3001,6 @@ static void multiple_early_media(void) {
 }
 #endif
 
-static void profile_call(bool_t avpf1, bool_t srtp1, bool_t avpf2, bool_t srtp2, const char *expected_profile) {
-	LinphoneCoreManager *marie = linphone_core_manager_new("marie_rc");
-	LinphoneCoreManager *pauline = linphone_core_manager_new("pauline_rc");
-	LinphoneProxyConfig *lpc;
-	const LinphoneCallParams *params;
-
-	if (avpf1) {
-		linphone_core_get_default_proxy(marie->lc, &lpc);
-		linphone_proxy_config_enable_avpf(lpc, TRUE);
-		linphone_proxy_config_set_avpf_rr_interval(lpc, 3);
-	}
-	if (avpf2) {
-		linphone_core_get_default_proxy(pauline->lc, &lpc);
-		linphone_proxy_config_enable_avpf(lpc, TRUE);
-		linphone_proxy_config_set_avpf_rr_interval(lpc, 3);
-	}
-	if (srtp1) {
-		if (linphone_core_media_encryption_supported(marie->lc, LinphoneMediaEncryptionSRTP)) {
-			linphone_core_set_media_encryption(marie->lc, LinphoneMediaEncryptionSRTP);
-		}
-	}
-	if (srtp2) {
-		if (linphone_core_media_encryption_supported(pauline->lc, LinphoneMediaEncryptionSRTP)) {
-			linphone_core_set_media_encryption(pauline->lc, LinphoneMediaEncryptionSRTP);
-		}
-	}
-
-	CU_ASSERT_TRUE(call(marie, pauline));
-	CU_ASSERT_TRUE(wait_for(marie->lc, pauline->lc, &marie->stat.number_of_LinphoneCallStreamsRunning, 1));
-	CU_ASSERT_TRUE(wait_for(marie->lc, pauline->lc, &pauline->stat.number_of_LinphoneCallStreamsRunning, 1));
-	params = linphone_call_get_current_params(linphone_core_get_current_call(marie->lc));
-	CU_ASSERT_STRING_EQUAL(linphone_call_params_get_rtp_profile(params), expected_profile);
-	params = linphone_call_get_current_params(linphone_core_get_current_call(pauline->lc));
-	CU_ASSERT_STRING_EQUAL(linphone_call_params_get_rtp_profile(params), expected_profile);
-
-	linphone_core_terminate_all_calls(marie->lc);
-	CU_ASSERT_TRUE(wait_for(marie->lc, pauline->lc, &marie->stat.number_of_LinphoneCallEnd, 1));
-	CU_ASSERT_TRUE(wait_for(marie->lc, pauline->lc, &pauline->stat.number_of_LinphoneCallEnd, 1));
-	CU_ASSERT_EQUAL(marie->stat.number_of_LinphoneCallConnected, 1);
-	CU_ASSERT_EQUAL(pauline->stat.number_of_LinphoneCallConnected, 1);
-
-	linphone_core_manager_destroy(pauline);
-	linphone_core_manager_destroy(marie);
-}
-
-static void avp_to_avp_call(void) {
-	profile_call(FALSE, FALSE, FALSE, FALSE, "RTP/AVP");
-}
-
-static void avp_to_avpf_call(void) {
-	profile_call(FALSE, FALSE, TRUE, FALSE, "RTP/AVP");
-}
-
-static void avp_to_savp_call(void) {
-	profile_call(FALSE, FALSE, FALSE, TRUE, "RTP/AVP");
-}
-
-static void avp_to_savpf_call(void) {
-	profile_call(FALSE, FALSE, TRUE, TRUE, "RTP/AVP");
-}
-
-static void avpf_to_avp_call(void) {
-	profile_call(TRUE, FALSE, FALSE, FALSE, "RTP/AVPF");
-}
-
-static void avpf_to_avpf_call(void) {
-	profile_call(TRUE, FALSE, TRUE, FALSE, "RTP/AVPF");
-}
-
-static void avpf_to_savp_call(void) {
-	profile_call(TRUE, FALSE, FALSE, TRUE, "RTP/AVPF");
-}
-
-static void avpf_to_savpf_call(void) {
-	profile_call(TRUE, FALSE, TRUE, TRUE, "RTP/AVPF");
-}
-
-static void savp_to_avp_call(void) {
-	profile_call(FALSE, TRUE, FALSE, FALSE, "RTP/SAVP");
-}
-
-static void savp_to_avpf_call(void) {
-	profile_call(FALSE, TRUE, TRUE, FALSE, "RTP/SAVP");
-}
-
-static void savp_to_savp_call(void) {
-	profile_call(FALSE, TRUE, FALSE, TRUE, "RTP/SAVP");
-}
-
-static void savp_to_savpf_call(void) {
-	profile_call(FALSE, TRUE, TRUE, TRUE, "RTP/SAVP");
-}
-
-static void savpf_to_avp_call(void) {
-	profile_call(TRUE, TRUE, FALSE, FALSE, "RTP/SAVPF");
-}
-
-static void savpf_to_avpf_call(void) {
-	profile_call(TRUE, TRUE, TRUE, FALSE, "RTP/SAVPF");
-}
-
-static void savpf_to_savp_call(void) {
-	profile_call(TRUE, TRUE, FALSE, TRUE, "RTP/SAVPF");
-}
-
-static void savpf_to_savpf_call(void) {
-	profile_call(TRUE, TRUE, TRUE, TRUE, "RTP/SAVPF");
-}
-
 static char *create_filepath(const char *dir, const char *filename, const char *ext) {
 	return ms_strdup_printf("%s/%s.%s",dir,filename,ext);
 }
@@ -3530,7 +3386,6 @@ test_t call_tests[] = {
 	{ "Early cancelled call", early_cancelled_call},
 	{ "Call with DNS timeout", call_with_dns_time_out },
 	{ "Cancelled ringing call", cancelled_ringing_call },
-	{ "Call failed because of codecs", call_failed_because_of_codecs },
 	{ "Simple call", simple_call },
 	{ "Call with timeouted bye", call_with_timeouted_bye },
 	{ "Direct call over IPv6", direct_call_over_ipv6},
@@ -3607,22 +3462,6 @@ test_t call_tests[] = {
 	{ "Call established with rejected RE-INVITE in error", call_established_with_rejected_reinvite_with_error},
 	{ "Call redirected by callee", call_redirect},
 	{ "Call with specified codec bitrate", call_with_specified_codec_bitrate},
-	{ "AVP to AVP call", avp_to_avp_call },
-	{ "AVP to AVPF call", avp_to_avpf_call },
-	{ "AVP to SAVP call", avp_to_savp_call },
-	{ "AVP to SAVPF call", avp_to_savpf_call },
-	{ "AVPF to AVP call", avpf_to_avp_call },
-	{ "AVPF to AVPF call", avpf_to_avpf_call },
-	{ "AVPF to SAVP call", avpf_to_savp_call },
-	{ "AVPF to SAVPF call", avpf_to_savpf_call },
-	{ "SAVP to AVP call", savp_to_avp_call },
-	{ "SAVP to AVPF call", savp_to_avpf_call },
-	{ "SAVP to SAVP call", savp_to_savp_call },
-	{ "SAVP to SAVPF call", savp_to_savpf_call },
-	{ "SAVPF to AVP call", savpf_to_avp_call },
-	{ "SAVPF to AVPF call", savpf_to_avpf_call },
-	{ "SAVPF to SAVP call", savpf_to_savp_call },
-	{ "SAVPF to SAVPF call", savpf_to_savpf_call },
 	{ "Call with in-dialog UPDATE request", call_with_in_dialog_update },
 	{ "Call with in-dialog codec change", call_with_in_dialog_codec_change },
 	{ "Call with in-dialog codec change no sdp", call_with_in_dialog_codec_change_no_sdp },
diff --git a/tester/liblinphone_tester.h b/tester/liblinphone_tester.h
index 0ae708b70..5f257bb08 100644
--- a/tester/liblinphone_tester.h
+++ b/tester/liblinphone_tester.h
@@ -62,6 +62,7 @@ extern test_suite_t log_collection_test_suite;
 extern test_suite_t transport_test_suite;
 extern test_suite_t player_test_suite;
 extern test_suite_t dtmf_test_suite;
+extern test_suite_t offeranswer_test_suite;
 
 
 extern int liblinphone_tester_nb_test_suites(void);
@@ -293,6 +294,7 @@ bool_t call_with_test_params(LinphoneCoreManager* caller_mgr
 
 bool_t call(LinphoneCoreManager* caller_mgr,LinphoneCoreManager* callee_mgr);
 void end_call(LinphoneCoreManager *m1, LinphoneCoreManager *m2);
+void disable_all_audio_codecs_except_one(LinphoneCore *lc, const char *mime, int rate);
 stats * get_stats(LinphoneCore *lc);
 LinphoneCoreManager *get_manager(LinphoneCore *lc);
 const char *liblinphone_tester_get_subscribe_content(void);
diff --git a/tester/offeranswer_tester.c b/tester/offeranswer_tester.c
new file mode 100644
index 000000000..b9de6a879
--- /dev/null
+++ b/tester/offeranswer_tester.c
@@ -0,0 +1,297 @@
+/*
+	liblinphone_tester - liblinphone test suite
+	Copyright (C) 2013  Belledonne Communications SARL
+
+	This program is free software: you can redistribute it and/or modify
+	it under the terms of the GNU General Public License as published by
+	the Free Software Foundation, either version 2 of the License, or
+	(at your option) any later version.
+
+	This program is distributed in the hope that it will be useful,
+	but WITHOUT ANY WARRANTY; without even the implied warranty of
+	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+	GNU General Public License for more details.
+
+	You should have received a copy of the GNU General Public License
+	along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+
+#include <stdio.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include "CUnit/Basic.h"
+#include "linphonecore.h"
+#include "lpconfig.h"
+#include "private.h"
+#include "liblinphone_tester.h"
+
+static int get_codec_position(const MSList *l, const char *mime_type, int rate){
+	const MSList *elem;
+	int i;
+	for (elem=l, i=0; elem!=NULL; elem=elem->next,i++){
+		PayloadType *pt=(PayloadType*)elem->data;
+		if (strcasecmp(pt->mime_type, mime_type)==0 && pt->clock_rate==rate) return i;
+	}
+	return -1;
+}
+
+/*check basic things about codecs at startup: order and enablement*/
+static void start_with_no_config(void){
+	LinphoneCoreVTable vtable={0};
+	LinphoneCore *lc=linphone_core_new(&vtable, NULL, NULL, NULL);
+	const MSList *codecs=linphone_core_get_audio_codecs(lc);
+	int opus_codec_pos;
+	int speex_codec_pos=get_codec_position(codecs, "speex", 8000);
+	int speex16_codec_pos=get_codec_position(codecs, "speex", 16000);
+	PayloadType *pt;
+	opus_codec_pos=get_codec_position(codecs, "opus", 48000);
+	if (opus_codec_pos!=-1) CU_ASSERT_TRUE(opus_codec_pos==0);
+	CU_ASSERT_TRUE(speex16_codec_pos<speex_codec_pos);
+	
+	pt=linphone_core_find_payload_type(lc, "speex", 16000, 1);
+	CU_ASSERT_PTR_NOT_NULL(pt);
+	if (pt) {
+		CU_ASSERT_TRUE(linphone_core_payload_type_enabled(lc, pt)==TRUE);
+	}
+	linphone_core_destroy(lc);
+}
+
+static void check_payload_type_numbers(LinphoneCall *call1, LinphoneCall *call2, int expected_number){
+	const LinphoneCallParams *params=linphone_call_get_current_params(call1);
+	const PayloadType *pt=linphone_call_params_get_used_audio_codec(params);
+	CU_ASSERT_PTR_NOT_NULL(pt);
+	if (pt){
+		CU_ASSERT_TRUE(linphone_core_get_payload_type_number(linphone_call_get_core(call1),pt)==expected_number);
+	}
+	params=linphone_call_get_current_params(call2);
+	pt=linphone_call_params_get_used_audio_codec(params);
+	CU_ASSERT_PTR_NOT_NULL(pt);
+	if (pt){
+		CU_ASSERT_TRUE(linphone_core_get_payload_type_number(linphone_call_get_core(call1),pt)==expected_number);
+	}
+}
+
+static void simple_call_with_different_codec_mappings(void) {
+	int begin;
+	int leaked_objects;
+	LinphoneCoreManager* marie;
+	LinphoneCoreManager* pauline;
+	LinphoneCall *pauline_call;
+
+	belle_sip_object_enable_leak_detector(TRUE);
+	begin=belle_sip_object_get_object_count();
+
+	marie = linphone_core_manager_new( "marie_rc");
+	pauline = linphone_core_manager_new( "pauline_rc");
+	
+	disable_all_audio_codecs_except_one(marie->lc,"pcmu",-1);
+	disable_all_audio_codecs_except_one(pauline->lc,"pcmu",-1);
+	
+	/*marie set a fantasy number to PCMU*/
+	linphone_core_set_payload_type_number(marie->lc,
+		linphone_core_find_payload_type(marie->lc, "PCMU", 8000, -1),
+		104);
+	
+	CU_ASSERT_TRUE(call(marie,pauline));
+	pauline_call=linphone_core_get_current_call(pauline->lc);
+	CU_ASSERT_PTR_NOT_NULL(pauline_call);
+	if (pauline_call){
+		LinphoneCallParams *params;
+		check_payload_type_numbers(linphone_core_get_current_call(marie->lc), pauline_call, 104);
+		/*make a reinvite in the other direction*/
+		linphone_core_update_call(pauline->lc, pauline_call, 
+			params=linphone_core_create_call_params(pauline->lc, pauline_call));
+		linphone_call_params_unref(params);
+		CU_ASSERT_TRUE(wait_for(pauline->lc,marie->lc,&pauline->stat.number_of_LinphoneCallUpdating,1));
+		CU_ASSERT_TRUE(wait_for(pauline->lc,marie->lc,&marie->stat.number_of_LinphoneCallUpdatedByRemote,1));
+		CU_ASSERT_TRUE(wait_for(pauline->lc,marie->lc,&pauline->stat.number_of_LinphoneCallStreamsRunning,2));
+		CU_ASSERT_TRUE(wait_for(pauline->lc,marie->lc,&marie->stat.number_of_LinphoneCallStreamsRunning,2));
+		/*payload type numbers shall remain the same*/
+		check_payload_type_numbers(linphone_core_get_current_call(marie->lc), pauline_call, 104);
+	}
+
+	end_call(marie,pauline);
+	linphone_core_manager_destroy(marie);
+	linphone_core_manager_destroy(pauline);
+
+	leaked_objects=belle_sip_object_get_object_count()-begin;
+	CU_ASSERT_TRUE(leaked_objects==0);
+	if (leaked_objects>0){
+		belle_sip_object_dump_active_objects();
+	}
+}
+
+static void call_failed_because_of_codecs(void) {
+	int begin,leaked_objects;
+
+	belle_sip_object_enable_leak_detector(TRUE);
+	begin=belle_sip_object_get_object_count();
+
+	{
+		LinphoneCoreManager* marie = linphone_core_manager_new( "marie_rc");
+		LinphoneCoreManager* pauline = linphone_core_manager_new( "pauline_rc");
+		LinphoneCall* out_call;
+
+		disable_all_audio_codecs_except_one(marie->lc,"pcmu",-1);
+		disable_all_audio_codecs_except_one(pauline->lc,"pcma",-1);
+		out_call = linphone_core_invite_address(pauline->lc,marie->identity);
+		linphone_call_ref(out_call);
+		CU_ASSERT_TRUE(wait_for(pauline->lc,marie->lc,&pauline->stat.number_of_LinphoneCallOutgoingInit,1));
+
+		/*flexisip will retain the 488 until the "urgent reply" timeout (I.E 5s) arrives.*/
+		CU_ASSERT_TRUE(wait_for_until(pauline->lc,marie->lc,&pauline->stat.number_of_LinphoneCallError,1,7000));
+		CU_ASSERT_EQUAL(linphone_call_get_reason(out_call),LinphoneReasonNotAcceptable);
+		CU_ASSERT_EQUAL(marie->stat.number_of_LinphoneCallIncomingReceived,0);
+		CU_ASSERT_EQUAL(marie->stat.number_of_LinphoneCallReleased,0);
+
+		linphone_call_unref(out_call);
+		linphone_core_manager_destroy(marie);
+		linphone_core_manager_destroy(pauline);
+	}
+	leaked_objects=belle_sip_object_get_object_count()-begin;
+	CU_ASSERT_TRUE(leaked_objects==0);
+	if (leaked_objects>0){
+		belle_sip_object_dump_active_objects();
+	}
+}
+
+
+static void profile_call(bool_t avpf1, bool_t srtp1, bool_t avpf2, bool_t srtp2, const char *expected_profile) {
+	LinphoneCoreManager *marie = linphone_core_manager_new("marie_rc");
+	LinphoneCoreManager *pauline = linphone_core_manager_new("pauline_rc");
+	LinphoneProxyConfig *lpc;
+	const LinphoneCallParams *params;
+
+	if (avpf1) {
+		linphone_core_get_default_proxy(marie->lc, &lpc);
+		linphone_proxy_config_enable_avpf(lpc, TRUE);
+		linphone_proxy_config_set_avpf_rr_interval(lpc, 3);
+	}
+	if (avpf2) {
+		linphone_core_get_default_proxy(pauline->lc, &lpc);
+		linphone_proxy_config_enable_avpf(lpc, TRUE);
+		linphone_proxy_config_set_avpf_rr_interval(lpc, 3);
+	}
+	if (srtp1) {
+		if (linphone_core_media_encryption_supported(marie->lc, LinphoneMediaEncryptionSRTP)) {
+			linphone_core_set_media_encryption(marie->lc, LinphoneMediaEncryptionSRTP);
+		}
+	}
+	if (srtp2) {
+		if (linphone_core_media_encryption_supported(pauline->lc, LinphoneMediaEncryptionSRTP)) {
+			linphone_core_set_media_encryption(pauline->lc, LinphoneMediaEncryptionSRTP);
+		}
+	}
+
+	CU_ASSERT_TRUE(call(marie, pauline));
+	CU_ASSERT_TRUE(wait_for(marie->lc, pauline->lc, &marie->stat.number_of_LinphoneCallStreamsRunning, 1));
+	CU_ASSERT_TRUE(wait_for(marie->lc, pauline->lc, &pauline->stat.number_of_LinphoneCallStreamsRunning, 1));
+	params = linphone_call_get_current_params(linphone_core_get_current_call(marie->lc));
+	CU_ASSERT_STRING_EQUAL(linphone_call_params_get_rtp_profile(params), expected_profile);
+	params = linphone_call_get_current_params(linphone_core_get_current_call(pauline->lc));
+	CU_ASSERT_STRING_EQUAL(linphone_call_params_get_rtp_profile(params), expected_profile);
+
+	linphone_core_terminate_all_calls(marie->lc);
+	CU_ASSERT_TRUE(wait_for(marie->lc, pauline->lc, &marie->stat.number_of_LinphoneCallEnd, 1));
+	CU_ASSERT_TRUE(wait_for(marie->lc, pauline->lc, &pauline->stat.number_of_LinphoneCallEnd, 1));
+	CU_ASSERT_EQUAL(marie->stat.number_of_LinphoneCallConnected, 1);
+	CU_ASSERT_EQUAL(pauline->stat.number_of_LinphoneCallConnected, 1);
+
+	linphone_core_manager_destroy(pauline);
+	linphone_core_manager_destroy(marie);
+}
+
+static void avp_to_avp_call(void) {
+	profile_call(FALSE, FALSE, FALSE, FALSE, "RTP/AVP");
+}
+
+static void avp_to_avpf_call(void) {
+	profile_call(FALSE, FALSE, TRUE, FALSE, "RTP/AVP");
+}
+
+static void avp_to_savp_call(void) {
+	profile_call(FALSE, FALSE, FALSE, TRUE, "RTP/AVP");
+}
+
+static void avp_to_savpf_call(void) {
+	profile_call(FALSE, FALSE, TRUE, TRUE, "RTP/AVP");
+}
+
+static void avpf_to_avp_call(void) {
+	profile_call(TRUE, FALSE, FALSE, FALSE, "RTP/AVPF");
+}
+
+static void avpf_to_avpf_call(void) {
+	profile_call(TRUE, FALSE, TRUE, FALSE, "RTP/AVPF");
+}
+
+static void avpf_to_savp_call(void) {
+	profile_call(TRUE, FALSE, FALSE, TRUE, "RTP/AVPF");
+}
+
+static void avpf_to_savpf_call(void) {
+	profile_call(TRUE, FALSE, TRUE, TRUE, "RTP/AVPF");
+}
+
+static void savp_to_avp_call(void) {
+	profile_call(FALSE, TRUE, FALSE, FALSE, "RTP/SAVP");
+}
+
+static void savp_to_avpf_call(void) {
+	profile_call(FALSE, TRUE, TRUE, FALSE, "RTP/SAVP");
+}
+
+static void savp_to_savp_call(void) {
+	profile_call(FALSE, TRUE, FALSE, TRUE, "RTP/SAVP");
+}
+
+static void savp_to_savpf_call(void) {
+	profile_call(FALSE, TRUE, TRUE, TRUE, "RTP/SAVP");
+}
+
+static void savpf_to_avp_call(void) {
+	profile_call(TRUE, TRUE, FALSE, FALSE, "RTP/SAVPF");
+}
+
+static void savpf_to_avpf_call(void) {
+	profile_call(TRUE, TRUE, TRUE, FALSE, "RTP/SAVPF");
+}
+
+static void savpf_to_savp_call(void) {
+	profile_call(TRUE, TRUE, FALSE, TRUE, "RTP/SAVPF");
+}
+
+static void savpf_to_savpf_call(void) {
+	profile_call(TRUE, TRUE, TRUE, TRUE, "RTP/SAVPF");
+}
+
+static test_t offeranswer_tests[] = {
+	{ "Start with no config", start_with_no_config },
+	{ "Call failed because of codecs", call_failed_because_of_codecs },
+	{ "Simple call with different codec mappings", simple_call_with_different_codec_mappings},
+	{ "AVP to AVP call", avp_to_avp_call },
+	{ "AVP to AVPF call", avp_to_avpf_call },
+	{ "AVP to SAVP call", avp_to_savp_call },
+	{ "AVP to SAVPF call", avp_to_savpf_call },
+	{ "AVPF to AVP call", avpf_to_avp_call },
+	{ "AVPF to AVPF call", avpf_to_avpf_call },
+	{ "AVPF to SAVP call", avpf_to_savp_call },
+	{ "AVPF to SAVPF call", avpf_to_savpf_call },
+	{ "SAVP to AVP call", savp_to_avp_call },
+	{ "SAVP to AVPF call", savp_to_avpf_call },
+	{ "SAVP to SAVP call", savp_to_savp_call },
+	{ "SAVP to SAVPF call", savp_to_savpf_call },
+	{ "SAVPF to AVP call", savpf_to_avp_call },
+	{ "SAVPF to AVPF call", savpf_to_avpf_call },
+	{ "SAVPF to SAVP call", savpf_to_savp_call },
+	{ "SAVPF to SAVPF call", savpf_to_savpf_call },
+};
+
+test_suite_t offeranswer_test_suite = {
+	"Offer-answer",
+	NULL,
+	NULL,
+	sizeof(offeranswer_tests) / sizeof(offeranswer_tests[0]),
+	offeranswer_tests
+};
diff --git a/tester/tester.c b/tester/tester.c
index 8c09b90f1..d3a34a375 100644
--- a/tester/tester.c
+++ b/tester/tester.c
@@ -420,6 +420,7 @@ void liblinphone_tester_set_writable_dir_prefix(const char* writable_dir_prefix)
 void liblinphone_tester_init(void) {
 	add_test_suite(&setup_test_suite);
 	add_test_suite(&register_test_suite);
+	add_test_suite(&offeranswer_test_suite);
 	add_test_suite(&call_test_suite);
 	add_test_suite(&message_test_suite);
 	add_test_suite(&presence_test_suite);