H323 One-Way Audio After Transfer/Park/Hold

[dgahm]

I have router FXO ports using H323v2 (tcl script autoattendant)with Call Manager 3.3.3 SR4A. The calls complete OK, but if they are parked or transferred, the audio is one-way inbound when picked up again. If I use MTP with the CCM gateway they work fine. This is OK where I have plenty of bandwidth, but I am turning up 3 sites that can only handle a couple G729 compressed RTP header streams over the WAN, so MTP using my central site transcoders is not an option. Most of these calls terminate on an IP phone at the same site and will run G711 if kept in the same location.

This is probably an easy config setting, but I'm not finding it. Anybody have the silver bullet here?

[dweiner]

A couple things to check -

1) Make sure you have the global "voice rtp send-recv" in the router

2) Make sure to bind the H323 signaling to the interface with the IP address you set in CCM administration for the gateway. This should be a loopback address on the router, but doesn't have to be. Under the interface use "h323-gateway voip bind srcaddr ???.???.???.???" and "h323-gateway voip interface"

There are a couple good links for this -

Specific info for troubleshooting this issue can be found at:

http://www.cisco.com/en/US/partner/products/sw/voicesw/ps556/products_tech_note09186a0080115a52.shtml

General troubleshooting of one-way audio is here:

http://www.cisco.com/en/US/partner/tech/tk652/tk698/technologies_tech_note09186a008009484b.shtml

[dgahm]

Thanks for the info. I had everything except the "voice rtp send-rcv", but adding it did not fix this issue. I am thinking this problem stems from the lack of Call Manager H450 transfer support.

[dweiner]

I really don't see where H.450 comes into this, so I set this up in my lab & have no problems with one-way audio on transfer or park. What script are you using for AA? What IOS? On 12.2.15ZJ3 I copied over the enter_destination.au onto flash, then configured the following:

!

username 999

!

aaa new-model

!

!

aaa authentication login h323 local

!

dial-peer voice 999 pots

destination-pattern 999

application clid_authen_col_npw

port 1/0/1

!

dial-peer voice 1000 voip

preference 1

destination-pattern 1...

session target ipv4:10.1.13.5

dtmf-relay h245-alphanumeric

codec g711ulaw

no vad

!

dial-peer voice 1002 voip

preference 2

destination-pattern 1...

session target ipv4:10.1.13.6

dtmf-relay h245-alphanumeric

codec g711ulaw

no vad

!

I used "h323 interface" and "h323-gateway voip bind srcaddr 10.1.12.254" on my ethernet interface. My test worked with our without'voice rtp send-recv' in the config., but that's something you want in there anyway.

[dgahm]

Thanks for taking the time to test this.

I can change to a connect PLAR on the FXO port, and have the same problem so it is not the tcl script.

I am testing with 12.3.4T1 currently, but have tried several IOS versions including 12.2.15ZJ3.

One difference is that I am using loopback interfaces for the H323 interface bind, but I just tried changing to an ethernet interface with the same results.

Maybe a Call Manager service parameter, but all H323 are set for default except for fast start which is true, and I have tried changing that.

I am baffled that this is working for you. What version CCM are you running? And your gateway MTP box is unchecked?

[mlohnert]

Hi,

I had the same issue, actually using BRI ports for PSTN connect. I opened a TAC case and was told to 'work around' it by either disabling H323 FastStart on enabling MTP. Neither is really a solution, since MTP just chews up too much bandwidth at remote sites, and no FastStart introduces a 3-5 sec lag on audio channel setup.

Well, from what I understood transfer/hold/park just won't work with FastStart enabled... But it'd be great if someone found a way to get it to work...

Cheers,

ML