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ISDN GW 3421 no incoming video to SIP endpoints after 2.2 upgrade

I've just upgraded our ISDN gateway 3421 from version 2.0 to version 2.2.

After the upgrade, H323 endpoints can dial in and out fine, but the SIP E20 connects OK but gets no incoming video (outgoing video is OK).  This happens on both inbound and outbound dialling.

Our ISDN GW is set up so that incoming and outgoing calls are H323, so the VCS-C is performing interworking when the SIP endpoint is involved.  I tried registering the E20 as H323 and it works properly via ISDN.  All other SIP/H323 interworking scenarios work OK.  The E20 and ISDN GW are in the same subzone.

The E20 has outgoing transport type set to TCP and the local zone configuration is set to "Auto" for encryption mode.

VCS is 7.2, E20 is TE4.1.3, ISDN GW is 2.2.

Any ideas where to start looking?                  


ISDN GW 3421 no incoming video to SIP endpoints after 2.2 upgrad

I'll also add that I tried disabling H264 to force H263 but no luck.

Cisco Employee

ISDN GW 3421 no incoming video to SIP endpoints after 2.2 upgrad

Hi Nick,

You can try to hold the call and resume it and see is video is working ( this will send new invite )? Just for test .

As per release note of 2.2 it is tested with TE 4.1.1.

from release note .

Cisco IP Video Phone E20

TE4.1  Tested SIP, H.323, and Unified CM.

  For encrypted SIP calls with content disabled, using

hold/resume causes encryption to fail on the resume


It was not tested with TE 4.1.3 as gate way software release earlier in jan - 2012 and TE released last month .

You can downgrade E 20 to TE 4.1. and see if it is working . If it is working then open TAC case with following working and non working logs. .

Required logs :

E20 - SIP logs

VCS - Application log

G/W : Isdn log and H323/SIp log .


Kind regards,


ISDN GW 3421 no incoming video to SIP endpoints after 2.2 upgrad

Thanks, I'll try your suggestion and post the results.

Re: ISDN GW 3421 no incoming video to SIP endpoints after 2.2 up


Tried Hold/Resume and downgrading to TE4.1.1.  Under all scenarios, it still displays the same symptoms.

I also tried turning off TLS on the VCS.  The call used TCP and said "Encryption off" on the E20 but the problem still occured.

Is there anything else I should try before logging with the TAC?

ISDN GW 3421 no incoming video to SIP endpoints after 2.2 upgrad

As always, a exect description of the deployment and scenario (here for example what is the remote infrastruture you are trying to connect).

I would not use TCP, TLS is the better choice :-)

The latest is VCS X7.2.2 which could be worth giving a try.

Check your firewalls for L3 functionality

Check the remote site and your codec settings (try enable / disable h264 for example).

Which bandwidth do you use? Did you try less/more?

How do other endpoints (set to sip on an outbound call) and jabber video behave?

Did you to sip enable the isdn-gw + neigbor zone to it if it behaves different?

Did you try using h323 on the e20 to see if it behaves different?

Do you know others with a ISDN GW and a E20 who can do a test call to the same number?

Please remember to rate helpful responses and identify

Re: ISDN GW 3421 no incoming video to SIP endpoints after 2.2 up

Some of this was answered in the initial post, but here's everything:

I am using TLS usually, I just disabled it as a test to see if the problem related to encryption.

Re: VCS 7.2.2 - yes it could be worth a try, but in this particular environment I've only got one VCS-C so the upgrade would need to be scheduled out of hours etc (My other environment is the one with lots of spare toys )

No firewalls between E20, VCS and ISDN GW.

I tried disabling H264 on the GW (was in the first post)

Other endpoints:  This environment doesn't have any other SIP endpoints.  I may be able to register something elese as SIP soon to test, hopefully.

Registering the E20 as H323 makes it work (was in the first post) - this leads me to suspect it could be interworking related.

Re: SIP on the ISDN GW - I did try enabling it, but from what I can see it only applies to inbound calls on ISDN as you can only register an ISDN prefix on VCS via H323.  The problem occurs on both inbound and outbound calls, but I haven't tried dialling inbound to E20 via SIP.

Re: Someone else with ISDN GW and E20 - I don't unfortunately.  Note that I've tried multiple ISDN endpoints, including dialling out and then back in to our own ISDN GW.

Re: Bandwidth - The ISDN GW is limited to 512Kbps per call, 3 calls total.  I did try lowering the call rate to 512kbps and 256kbps but no luck.

Call flow is SIP E20 > VCS-C > H323 ISDN GW > ISDN

Re: ISDN GW 3421 no incoming video to SIP endpoints after 2.2 up

Hi Nick,

I think you should check the logs on VCS to see if the media negotiation happens correctly. You could check media negotiaton from E20 to VCS and from VCS to Gateway. It can be useful to check if there is some problem related to VCS's interworking or to ISDN negotiation, or something else.


Paulo Souza

Please rate replies and mark question as "answered" if applicable.

Paulo Souza Was my response helpful? Please rate useful replies and remember to mark any solved questions as "answered".