Ask the Cisco VIP: Troubleshooting SIP in Cisco Unified communications

[ciscomoderator]

Troubleshooting SIP in Cisco Unified communications deployments with Cisco VIP Ayodeji Okanlawon

This is a Q&A Ask the Expert Session continuation from the Live Webcast

Ask your questions on Session Initiation Protocol (SIP) and how it is redefining our UC world.The Session Initiation Protocol (SIP) is a signaling communications protocol, widely used for controlling multimedia communication sessions such as voice and video calls over Internet Protocol (IP) networks.

Featured Expert

Ayodeji Okanlawon, a Cisco Designated VIP, is the Lead Consultant Engineer for Global Solutions Design and Engineering at Verizon Business. In his past, he has worked at Intact IS, NCS Global, and Schlumberger Information Solutions. His experience includes development of design and deployment of large scale IP telephony projects on Cisco Call Manager platforms, Cisco Voice gateways, Cisco Jabber cloud and on premise solution. His expertise includes SIP solutions, CUBE design and Deployment, Troubleshooting: Voice gateways, CUCM, Unity connection, CUPS. Deji has been awarded the Cisco Designated VIP in 2013 and 2014. Deji holds a Bachelor of Science (BS), Electrical and Electronics Engineering, Second Class Upper from Obafemi Awolowo University.  

According to Deji, “If you want to advance your career, if you’re serious about your skill sets, you’ve got to be in the forums.”  (Read the Interview >>)

We look forward to your participation. This event is open to all, including partners.

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Deji might not be able to answer each question due to the high volume expected during this event. This event runs January 13 through January 23, 2015.  Visit this forum often to view responses to your questions and the questions of other community members.

[Mike Assel]

Deji, the reason for this is because the NAT'd endpoint is not NAT'd correctly.  The IP address it uses for outbound connections is different than the one used for inbound.  The address used for inbound connections is the 47.x.x.x address.  For me that makes it even more confusing as to why the outbound calls were able to work.  I'm not sure I can do anymore testing on this because we fixed the SIP inspection issue that was causing the inbound calls to fail.  Can you think of any situations where an endpoint would send the media stream to the IP address it received the INVITE from, rather than the address in the (c) line?  Does early offer play into this at all?  Thanks,  Mike

[Ayodeji Okanlawon]

No I have never seen that and I doubt if any vendor will design their system to work that way. The From header is usually used only for display purposes. This must be related some how to the Nating on the device.

No Early offer doesn't play any role at all. EO will just include SDP in the INVITE and will include the c line to indicate where media should be sent to

[Ayodeji Okanlawon]

Mike,

Do you have an update on this? Can you get the diagnostics logs?