No audio over IP phones 2

[MrYotsuya]

I have a remote site that has a Cisco Pix and about 2 ip phones. The ip phones work normal when you dial from a digital phone but a IP to IP or IP to dial-out results in dead air. QOS is enabled and they have worked fine until last week. Is there anything I should look at?

 

[allenmac]

Were any changes to any of the network gear involved made just prior to the problem surfacing?

 

[MrYotsuya]

None at all thats what makes it odd, I am getting a crypto map error I may have to post in the Cisco forums, here it is just in case:

Group = x.x.x.x, IP = x.x.x.x, Rejecting IPSec tunnel: no matching crypto map entry for remote proxy x.x.x.0/255.255.252.0/0/0 local proxy x.x.x.0/255.255.255.0/0/0 on interface Outside

 

[allenmac]

It sounds like there is only one-way connectivity between some of your devices. Or connections are only being allowed if they are initiated from one direction.

It is strange that a TDM phone can call an IP phone, but an IP phone cannot call out on a TDM trunk.

 

[MrYotsuya]

Yea thats is odd, Turns out the IPsec is all fubar, I appreciate the help, I'm working through that nonsense now!

 

[MrYotsuya]

Found IT!! The Net Masks in the ACL of the Pix did not match for our network. Dunno HOW that got changed as its worked all this time before, two way conversations can now be had!

 

[MrYotsuya]

Spoke too soon!!! gah! I am able to communicate IP phone to IP phone...but Outbound calls are silence. I called the office from my Cell phone and Heard nothing. Any ideas on this one?

 

[allenmac]

TDM to IP calls require the use of your DSP channels. Make sure the phones can talk to them.

 

[MrYotsuya]

I know I have seen those in Element manager only I cant recall where, those are the MGC cars with the IPs corret?

 

[MrYotsuya]

No dice, It is able to communicate with the channels (took me awhile to find them) There are no errors in my firewall log so all traffic is going thorugh no problem but just these two sites cannot call out.

 

[MrYotsuya]

Anyone? I have communication, In the Pix Logs I see the Sessions being built for the call and no errors like before but I get no Courtesy Ring and no audio whatsoever on IP to Outside calls, IP to DN calls are just fine....and its only at two sites! My other IP phones work fine.

 

[vztech]

Have you tried an Digital or Analog to IP set internal call?
if so what are the results?

It's only dialtone!!!

 

[MrYotsuya]

yes internal calls are fine, and its only the IP sets at two branch offices.

 

[gwebster]

You have a network routing problem somewhere. For an IP to IP call, the voice packets go directly between the two IP Phones so trace and see where they are blocked. For an IP to outside, the voice packets are going directly between the IP Phone and the DSP on the media gateway. Again trace to see where blocked.

 

[MrYotsuya]

Is there a way to do the trace with teh CS1000? I have done the traces on the network side and I do not show anything being blocked.

 

[allenmac]

You can do a tracert directly from the IP set.

Press the Services button 2x quickly then select the Network Diagnostic tool. Enter the IP address of another IP telephone at a distant location and choose either Ping or TracRt. Try doing this from the far end set back to your local set as well.

 

[MrYotsuya]

Thanks! That Helps a lot, I'm heading to the site to test it now.

 

[allenmac]

You can also initiate the same tests from the command line of the signaling server that one of the phones is registered to.

The commands are rPing, rPingStop, rTraceRoute, rTraceRouteStop

The command syntax for rPing and rTraceRoute is [IP | TN, IP, count]
The command syntax for rPingStop and rTraceRouteStop is [IP | TN]

running the tests from the signaling server should allow you to initiate the tests remotely, and observe/capture the results.

 

[MrYotsuya]

No dice, just to make sure I am checking that the sets can communicate to the TLAN correct?

 

[allenmac]

Yes, you should be able to ping the IP sets from each other, and get a good tracert between the sets - both on the T-LAN.