Calls without audio (but not all, only 20%)

[rparrat666]

Hi Experts,

I’m having a big and rare issue.

When calling to some phones (like 2797901, 2797956, 2797978) from outside to inside the company, most of the calls connect ok, but some of them (like 20%) they just don’t have audio (neither I can listen something, nor the user on the other side).

What its pretty rare, is that it not only looks to be at random, but also, that if the guy at the opposite side of the phone push the buttons of the iphone, u can listen that sound clearly.  :S

The voice gateway is a Cisco 2621XM using c2600-is-mz.122-8.T10

I’m adding the run config, and some outputus I took of the “sh voice call summary” and “sh voice call” while I was having the issue. My call is on the port 1/0:0.2 but I been checking and it also happens on other ports (like 1/0:0.5) 

We are using teh controller E1 1/0, for those lines.

I’d been trying to figurate out the problem for a long time, but I don’t know to much about voice.

Please any help will be appreciated.

Thanks

[CHRIS CHARLEBOIS]

It sounds like a codec mismatch of some kind.  The fact that you can hear the DTMF tone when the far-end presses a button isn't very suprising; It just means that the DTMF tones are being carried out-of-band and re-created on the far end.  What kind of IP handsets are you using?  If you are using a Cisco IP Phone, you can press the help button (it has a ? on it) twice during a call to see info about that call.  It should tell you what codec the phone is sending, and what it thinks it's recieving, and how many packets are coming through.

[rparrat666]

Hi,

Thanks for the response.

Here is the data from a call that its ok

RX Type: G.711u                    TX Type:G.711u

RX Size: 20ms             TX Size:20ms

Avg Jtr: 1                     Max Jtr: 12

Rx Dics 0000              Rx Lost: 0000

MOS LQK: 4.5000

Media MOS LQK: 4.4924

Min MOS LQK: 4.3828

Max MOS LQK: 4.5000

Version MOS LQK: 0.95

And here is the data from a failed call

RX Type: G.711u                    TX Type:G.711u

RX Size: 20ms             TX Size:20ms

Avg Jtr: 1                     Max Jtr: 33

Rx Dics 0000              Rx Lost: 0001

MOS LQK: 4.5000

Media MOS LQK: 4.2163

Min MOS LQK: 2.7338

Max MOS LQK: 4.5000

Version MOS LQK: 0.95

[paolo bevilacqua]

If you reload the router, does it happen again ?

[rparrat666]

Does a reload should help?

I reload the router, without any change.

[rparrat666]

I'm adding some traces I capture with the Real time monitoring tool from the call manager, just at the moment I was having the issue.

The phone where I was calling is the 5585008800.

[rparrat666]

Looks we are hitting bug CSCdx66463. But can be fixed due to the devide is too old.

[Hythim Ali El Hadad]

Hi,

It is most likely a security issue

If you have a firewall, check that you have all RTP ports opened

If a call hit a closed port,no RTP will be passed

If it hit an opened port,RTP will be passed successfully

So you are finding this random behaviour

Wish this be helpful

Thanks