Ports, transports, and where a request can go

Visual

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A peer document can override a default. The default is the rule when the peer is silent.

Worked example

Read the OPTIONS Dissect the OPTIONS. The CSeq method token has to match the request line.

1. Paste the message into the dissector.
2. Find the request line and the CSeq.
3. Note the transport token in Via.

Fault

A large INVITE on UDP is retransmitted and then times out. The same peer answers when the request is sent on TCP.

Section 18 is why a large request moves to TCP or TLS.

Quiz

Ecosystem

Glossary, sister systems, and the integration seam for this room.

Quality management and recording QM scores interactions. The standardized way an SBC forks a session to a recorder is SIPREC.

Glossary · Ecosystem map · Ports · Troubleshooting