Wireless 7925 and MOH

[mightyking]

Hi Everyone,

There's no MOH with our Wireless 7925 phones. The mulicast is enabled across the Network and all other IP phones are working fine. We are usning CUCM 7.1.3 and the GW's are 3845's. I would appreciate if you could share your experience with me.

Thanks,

MK

[Jonathan Schulenberg]

One of the things I am NOT thankful for this year is VoWLAN, especially multicast. Just saying.

If your wired phones are working fine for multicast MoH than this is a wireless infrastructure problem and this thread should probably be moved. For starters though:

• Is there a WLC or are the APs autonomous?
  • If a WLC, what code version is it running?
    • Are the APs running CAPWAP, LWAPP, or HREAP?
  • If autonomous, what IOS code is the AP running?

[mightyking]

Hi Jonathan,

Sorry fo the delay, The WLCs are running 7.0.98.0 and the APs use CAPWAP. It looks like the issue is only for internal calls. The calls through PSTN have no problem.

Thanks,

MK

[Mishkin]

I know It's a very old discussion, but did you find a solution for this case?

[b.garczynski]

On the WLC 7 firmware I have seen a few problems with the new multicast to unicast feature. Unless you have a specific need I would disable the media stream options. I think your best option is to configure the WLC for multicast in unicast mode. This will use a bit more bandwidth, but the MOH performance will be much better. Make sure that the multicast MOH is enabled for the management interface of the WLC on the switch. The WLC will then distribute the multicast traffic to the correct client regardless of the virtual interface the SSID is tied to. Keep in mind though that multicast over 802.11 is not reliable as unicast traffic is. "Reliable" multicast is available with the media stream feature that I mentioned above, however I would wait at least one more release as the feature seems a bit unstable in my experience.

[mightyking]

Thanks for the reply, do I need to disable the Media stream options in the WLC or in the CCM? Please note that the GWs are sourcing the MOH streams.

Thanks,

MK

[b.garczynski]

You will need to disable the media streams on the WLC. You will also need to enable multicast in unicast mode on the WLC.

[mightyking]

Thanks,

I would like to understand why the same multicast MOH is working for the calls over PSTN but fails for the internal calls.  I don't think the Internal or external calls are processed differently from the WLC. They route the calls over the same vlan. Am I mistaken?

MK

[Jonathan Schulenberg]

This is probably the point you need to Wireshark this from the WLC and see what is being sent to the phone. The only gotcha I can think of is: are the PSTN-based calls you're testing a remote destination? Remote Destination phones (e.g. user cell phones) don't use multicast MoH for some bizarre reason.

[mightyking]

Hi Janothan,

Yes, the remote destination was a cell phone. But even when I dial the wireless number (10 digits to simulate PSTN) using an IP phone the MOH works when the Wireless phone puts the call on hold. Only the issue is with the internal calls

Thanks,

MK

[b.garczynski]

Maybe I did not understand the original issue properly. MOH does not work only when a 7925 places another internal IP phone on hold, regardless if it is a wireless or wired phone? Do you hear any beeps on the other end that would indicate MOH did not start properly? If you hear multicast music on hold on the 7925 at anytime it should be safe to assume multicast is routing properly into the WLC. I agree that a packet sniffer would be a good next step to see exactly what traffic is being sent/received by the WLC. 

[mightyking]

When a 7925 puts an internal call on hold, all we hear is DEAD AIR. My question is; does WLC treat the internal and external calls differentely? Doesn't it route the call to the VLANs where the wireless phone is in? If so, why the MOH works for the extenal calls but fails for the internal.

Thanks,

MK