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- A LANCOM VoIP router is connected to a Deutsche Telekom line with a SIP trunk.
- Connected to the LANCOM router is an ISDN telephone that has been assigned the MSN 123412. The # character is a wildcard for any number of digits, which is why the user 1234# is used when dialing MSN 123412.
- The call-routing table appears as shown below:
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6) The router sends an INVITE packet to the provider to initiate the call.
Info:
You can find for the INVITE packet in the trace by searching for the character string INVITE sip. The INVITE packet is a part of the SIP-Packet trace.
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- Sending datagram: This is an outbound packet sent by LANCOM router.
- The Request-LineLine consists of the INVITE sip followed by the target number (in this case +49240598765). The target number is primarily derived from the Request-Line.
- From: <sip:+492405123412: The phone number in the From field is the source number.
- To: <sip:49240598765: The Phone number in the To field is the target number.
- Call-ID: 1181155967@00a057467ed9: The Call-ID is a unique identifier that you can search for in the trace to output the SIP flow.
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