SIP 100 Trying vs 513 Message Too Large
SIP 100 (Trying) is a 1xx Provisional response, while 513 (Message Too Large) is a 5xx Server Failure response. 100 indicates that the request has been received by the next-hop server and an unspecified action is being taken to process it. The UAC should expect additional responses. In contrast, 513 means that the server was unable to process the request since the entire SIP message (not just the body) exceeded the size limit.
الوصف
The request has been received by the next-hop server and an unspecified action is being taken to process it. The UAC should expect additional responses.
متى تراه
Immediately after sending an INVITE. The proxy has received the call and is searching for the callee. This is the SIP equivalent of a dial tone.
كيفية الإصلاح
No fix needed — this is normal call setup behavior. If stuck on 100 Trying for too long, check network connectivity and proxy configuration.
الوصف
The server was unable to process the request since the entire SIP message (not just the body) exceeded the size limit.
متى تراه
When the total SIP message (headers + body) is too large. Different from 413 which refers only to the body.
كيفية الإصلاح
Reduce the message size by removing unnecessary headers or reducing the SDP size. Consider using UDP-compatible message sizes (< 1300 bytes).
الفروق الرئيسية
100 is a 1xx Provisional response, while 513 is a 5xx Server Failure response.
SIP 100: The request has been received by the next-hop server and an unspecified action is being taken to process it. The UAC should expect additional responses.
SIP 513: The server was unable to process the request since the entire SIP message (not just the body) exceeded the size limit.
You encounter 100 when immediately after sending an INVITE. The proxy has received the call and is searching for the callee. This is the SIP equivalent of a dial tone.
You encounter 513 when when the total SIP message (headers + body) is too large. Different from 413 which refers only to the body.
متى تستخدم أيًا منهما
For 100 (Trying): No fix needed — this is normal call setup behavior. If stuck on 100 Trying for too long, check network connectivity and proxy configuration. For 513 (Message Too Large): Reduce the message size by removing unnecessary headers or reducing the SDP size. Consider using UDP-compatible message sizes (< 1300 bytes).