One way audio

[adelainey]

I have an issue where making an outbound external call to two specific numbers, I get one way audio. The phones in question are on our telco's integrated business solution plan. (That is what they call it)
The phones are in a hunt group that will allow multiple phones to ring when one of the two phones are dialed. When they answer they can hear me but I cannot hear them. I spoke with the telco and they changed the type of hunt to ring in a circular pattern instead of ringing all phones and I this allowed two audio, as soon as they switch it back to ring all phones simultaneously, I am back to one way audio. Telco mentioned the RTP stream is being sent and I can see packets hit the cube but there is no packets received by the phone during the call.

Not even quite sure where to start with this one. Any help is greatly appreciated.

 

[gnrslash4life]

Do you get the RTP streams hitting your CUBE?

Certifications:
A+
Network+
CCENT
CCNA Voice
TVOICE
CAPPS
CIPTV1
CIPTV2

 

[adelainey]

What's the quickest way to check?

 

[gnrslash4life]

I would wireshark it.

Certifications:
A+
Network+
CCENT
CCNA Voice
TVOICE
CAPPS
CIPTV1
CIPTV2

 

[adelainey]

RTP streams hit the CUBE and the also come to the phone. Did a packet capture on the phone and can hear two audio from the capture but not on the phone...

 

[gnrslash4life]

I would say replace the phone and see what happens.

Certifications:
A+
Network+
CCENT
CCNA Voice
TVOICE
CAPPS
CIPTV1
CIPTV2

 

[adelainey]

This has been tested on 7 different phones.

 

[gnrslash4life]

So you're spanning the phone port and can hear audio but the phone itself cannot?

Certifications:
A+
Network+
CCENT
CCNA Voice
TVOICE
CAPPS
CIPTV1
CIPTV2

 

[adelainey]

That's correct.

 

[gnrslash4life]

That doesn't even make sense cause if the phone is receiving all the packets then how is no audio coming out. Did you try a different model of phone or the same one?

Certifications:
A+
Network+
CCENT
CCNA Voice
TVOICE
CAPPS
CIPTV1
CIPTV2

 

[adelainey]

I agree. It has me so confused. We have tested on Cisco 7821, 7841 and DX650 phones. We also have an Avaya phone system as well and there is no issue with those phones.

 

[adelainey]

Any other suggestions?

 

[gnrslash4life]

Actually, do you have a SCCP phone you can try?

Certifications:
A+
Network+
CCENT
CCNA Voice
TVOICE
CAPPS
CIPTV1
CIPTV2

 

[adelainey]

We do have a couple. I will try one and let you know.

 

[adelainey]

Tried an SCCP phone and same issue.

 

[gnrslash4life]

I would say open a TAC case.

Certifications:
A+
Network+
CCENT
CCNA Voice
TVOICE
CAPPS
CIPTV1
CIPTV2

 

[adelainey]

Just opened one this morning. Thanks for all your help. Anything else comes to mind let me know.

 

[adelainey]

Turns out TelCo was sending a recvonly invite. They refused to acknowledge this as an issue so TAC suggested I run the following on our sip profile on the CUBE;

request ANY sdp-header Audio-Attribute modify "a=inactive" "a=sendrecv"
request ANY sdp-header Audio-Attribute modify "a=recvonly" "a=sendrecv"
request ANY sdp-header Audio-Attribute modify "a=sendonly" "a=sendrecv"
response ANY sdp-header Audio-Attribute modify "a=inactive" "a=sendrecv"
response ANY sdp-header Audio-Attribute modify "a=recvonly" "a=sendrecv"
response ANY sdp-header Audio-Attribute modify "a=sendonly" "a=sendrecv"

No more one way issues.