[cisco-voip] Odd behaviour with Expressway and DNS SRV

Eric Pedersen PedersenE at bennettjones.com
Thu Jan 30 11:14:32 EST 2014


Did you convert an existing VCS to Expressway? If you have a SIP trunk to CUCM, did you configure to use a non-standard SIP port? Otherwise it won't work when you turn on Edge.

Is SIP UDP enabled on your VCS-E? It's off by default and if you haven't enabled it, your UDP SRV record will cause problems.

Eric

From: cisco-voip [mailto:cisco-voip-bounces at puck.nether.net] On Behalf Of Dana Tong
Sent: 29 January 2014 3:09 PM
To: cisco-voip at puck.nether.net (cisco-voip at puck.nether.net)
Subject: [cisco-voip] Odd behaviour with Expressway and DNS SRV

Good day all,

I had setup an Expressway for video traversal. B2B video was fine. But then in preparation for Collab Edge had the customer insert some SRV records and it screwed inbound video calls. Does anyone know the best practice for implementing these records?

The setup is:

Expressway E version 8.1
Expressway C version 8.1
CUCM version 9.1(2)SU1

Customer has a DNS alias of video.customer.com.au pointing to their Expressway.

Inbound and outbound video calls are fine. I have can make inbound calls to the MCU by using meeting at video.customer.com.au<mailto:meeting at video.customer.com.au>

Then we configured the following DNS SRV records:

_collab-edge._tcp.customer.com.au   -->   video.customer.com.au           tcp          8443
_xmpp-client._tcp.customer.com.au   -->   video.customer.com.au           tcp          5269
_xmpp-server._tcp.customer.com.au   -->   video.customer.com.au         tcp          5222
_sip._tcp.customer.com.au   -->   video.customer.com.au             tcp          5060
_sip._udp.customer.com.au   -->   video.customer.com.au           udp        5060
_sip._tls.customer.com.au   -->   video.customer.com.au               tcp          5061

Something in the SRV records for SIP caused inbound calls to stop working.

Inbound calls to meeting at video.customer.com.au<mailto:meeting at video.customer.com.au> fail. However inbound calls to meeting@<ip.address<mailto:meeting@%3cip.address>> continue to work.

The VCS Expressway was showing no inbound calls in "call history" or "search history".
Is there another way to check to see if the call is even hitting the Expressway?
The VCS E&C have both the domain of customer.com.au and video.customer.com.au. The endpoints, MCU, etc are registered to the VCS as endpoint at video.customer.com.au<mailto:endpoint at video.customer.com.au>

Is the Expressway getting confused with the two domains? Would anyone have a good working example of how Collaboration Edge should be deployed?
I have been referring to this guide: http://www.cisco.com/en/US/docs/voice_ip_comm/expressway/admin_guide/Cisco-Expressway-Administrator-Guide-X8-1.pdf


Cheers all.

D







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