SIP: 180 Ringing vs 183 Session Progress
2012-12-19 10:52
645 查看
If you know that the phone is ringing (an ALERT Q.931 message, for instance) you send a 180 Ringing.
If you receive a notification indicating that the call is progressing, but you do not know for sure whether the user is being alerted or not, you send a 183 Session Progress message.
Both can indicate early media with SDP. If there is no SDP, the end device (softphone/gateway/etc.) has to generate the ringback tone or progress tone.
Usually you will see 180 without SDP while 183 with SDP. It is a good practice to leave the tone generation for the endpoints.
If you get 183 you should open media connection because there is audio ready for them to hear.
If you set ringback var and ignore_early_media, both 180 and 183 will trigger your fake ringing. If you set instant_ringback=true then it will not wait for 18x it will start fake ringback instant (asterisk mode).
RFC3261:
21.1.2 180 Ringing
The UA receiving the INVITE is trying to alert the user. This
response MAY be used to initiate local ringback.
21.1.5 183 Session Progress
The 183 (Session Progress) response is used to convey information
about the progress of the call that is not otherwise classified. The
Reason-Phrase, header fields, or message body MAY be used to convey
more details about the call progress.
If you receive a notification indicating that the call is progressing, but you do not know for sure whether the user is being alerted or not, you send a 183 Session Progress message.
Both can indicate early media with SDP. If there is no SDP, the end device (softphone/gateway/etc.) has to generate the ringback tone or progress tone.
Usually you will see 180 without SDP while 183 with SDP. It is a good practice to leave the tone generation for the endpoints.
If you get 183 you should open media connection because there is audio ready for them to hear.
If you set ringback var and ignore_early_media, both 180 and 183 will trigger your fake ringing. If you set instant_ringback=true then it will not wait for 18x it will start fake ringback instant (asterisk mode).
RFC3261:
21.1.2 180 Ringing
The UA receiving the INVITE is trying to alert the user. This
response MAY be used to initiate local ringback.
21.1.5 183 Session Progress
The 183 (Session Progress) response is used to convey information
about the progress of the call that is not otherwise classified. The
Reason-Phrase, header fields, or message body MAY be used to convey
more details about the call progress.
相关文章推荐
- 180还是183?
- SIP 183 Session Progress Message
- Ectra Credit 180,181,182,183,184,185,186,187,188,189,190
- JSR180, SIP API for J2ME
- 祭奠·珍惜·祈福
- Activity切换动画·overridePendingTransition
- 读易[18]·企业组织结构剖析(坤)
- SIP中第三方呼叫控制(3PCC)建立流程
- 读易[13]·闲谈中医与AOP
- JAVA设计模式 · 策略模式
- 理想·环境·开源
- Jmeter那点事·ForEach和If控制器
- SIP 软电话开发环境的建立
- 每日一支TED——帕特里夏·瑞安:不要固执于英语
- 决战水源之巅·外传之御花园
- RFC学习笔记 -- 5245 ICE & 3261 SIP
- Cisco IP Phone 7960/7940 SCCP firmware 转换成SIP firmware过程
- 用户·角色·权限·表
- 冯·诺依曼体系和哈佛体系结构比较
- H323、H248(MGCP)、SIP三协议浅析