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.
描述
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.
何时出现
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.
如何修复
No fix needed — this is normal call setup behavior. If stuck on 100 Trying for too long, check network connectivity and proxy configuration.
描述
The server was unable to process the request since the entire SIP message (not just the body) exceeded the size limit.
何时出现
When the total SIP message (headers + body) is too large. Different from 413 which refers only to the body.
如何修复
Reduce the message size by removing unnecessary headers or reducing the SDP size. Consider using UDP-compatible message sizes (< 1300 bytes).
主要区别
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.
何时使用哪个
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).