OneWay audio in SIP

[yogesh bhalerao]

Hi All,

        I have Issue of ONEWAY audio in SIP my HO in India and Remote Location(out of india) ,

INDIA>> REMOTE

REMOTE>> INDIA

ON BOTH THE CALLS REMOTE LOCATION CAN HEAR US BUT WE ARE NOT ABLE TO  HEAR THEM ALSO ITS SAME BEHAVIOUS VIA IPHONES AND ANALO PHONES

INDIA:-CCM

REMOTE:-MATRIX PBX

1)HO to Remote location >>> IPSec Tunnel

2)We changed the ISP in Remote location and after that the problem of one way Audio started

3)Delted the recreated SIP Trunk Profile

4)Disabled MTP

5)restarted the Remote PBX

But Still we are stuck up,request you guyzz to please help me

Thanks in Advance

[Leo Laohoo]

You didn't describe your WAN link.

One-way-audio is normally associated with NAT-ing issues.

[yogesh bhalerao]

Hi,

    INDIA(internet lease line) and remote locations(normal ISP) we have IPsec tunnel between both the locations and policies have services ALL OPEN nuthing is blocked betwwen the subents

[Leo Laohoo]

2)We changed the ISP in Remote location and after that the problem of one way Audio started

Well, I disagree.  Something is being blocked after you "changed the ISP".

Either some mis-configurations in the remote-end router or your ISP forgot something.

[yogesh bhalerao]

Hi Leo,

          I checked with Remote ISP they said they have not blocked voice also in configuration we just changed the Public IP for the tunnel on remote and HO end and nuthing else.

[yogesh bhalerao]

Hi,

   I checked with the firewall configuration bidirectional policy is only there but no natting is involved in it

[Dennis Mink]

Yogesh,  I am still not clear on your set up.  The SIP trunk you are talking about, is that from CUCM to your provider, or where is that going to?

also can you ping between LAN subnets/voice subnets/phones?     If there is no NAT/FW as you say between the two locations, I wonder if you have changes your interesting traffic on the IPSEC tunnel configuration  (crypto map).

I dont believe in coincidences and it must be related to your change.

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[yogesh bhalerao]

Hi,

    The setup is as follows

EPBX---switch---F/W >>>>>>>> F/W -----Switch------CUCM

    REMOTE LOCATION                      HO

Ipsec tunnel Between them also remote/HO location policies all services allowed(bidirectonal policies at both the ends)

Remote location:-able to ping HO,CUCM,LAN subnet

HO:-Able to ping Remote EBPX

Call from HO>>> REMOTE :-REMOTE ABLE TO HEAR HO USERS VOICE BUT HO USERS NOT ABLE TO HEAR  REMOTE USERS VOICE

Call from REMOTE:- THE SAME THING IS HAPPENING NOT ABLE TO HEAR REMOTE USERS VOICE

[Zaher Juha]

I faced the same problem between two regions

the probelm was in the network

how can you make sure from it

ping both sides from each side

the network team did something i don't know what is it even the ping was working from one side not both

after they fix it everything works perfectly

[yogesh bhalerao]

Hi Zaher,

            I am able to ping from HO and Remote Location,my rest of data is working properly and i am able to access it so its not issue with Network i suppose

[Dennis Mink]

The fact that you can ping DOES NOT rule out a network issue, it just proves that ICMP works, and routing works.

there is 2 things I would do:

1-check the trace files on cucm of a test call, and make absolutely sure there is no anomalies.

2-use wireshark at both ends, using IP communicator, and see if both ends are actually sending RTP from the endpoint.

Good luck

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[yogesh bhalerao]

HI Mink,

            Thanks for your reply i tried packet cpature at both the ends but i can not see any RTP request from both the ends but strangley calls are getting connected but only one way audio from remote to HO,checked my EPBX in HO is not blocking anything and using g.711 codec but i can not find any rtp requests

Any thoughts???

[Dennis Mink]

If you have one way voice, and HO can hear remote, on a machine at HO, running IP communicator and wireshark, you should be able to capture RTP, if not, you are doing something wrong, possibly with your capture or display filters on wireshark. I suggest to just capure bast on the ip address of the remote host, because RTP will be point to point between the two phones.

also, you could use an access-list with a permit and log it. so on your remote site router someting like:

access-list 100 permit ip host    log

access-list 100  permit ip any any

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[yogesh bhalerao]

Hi Mink,

             Yesterday we reconfigured remote EPBX also we did calling audi/video via Microsoft Lync it was working perfeclty via LYNC but again via analog/IP Phone the same issue

    ISP from both the ends says nothing is blocked