VG224 Modem Calls

[ankit.joshi]

Hi Guys,

Can anyone please help me to check why Inbound calls to modem fails to establish through VG224 as per below scenario.

Inbound Call------>VoiceGateway--(H323)--->CUCM---(MGCP)-->VG224--->Modem

MGCP modem passthrough is configured on VG224 with NSE

and

voice service voip

modem passthrough nse codec g711alaw

CUCM 7.1.3

VG224 - 12.4(9)T7

When we call inbound from externally we can hear it is ringing but modem is not able to pick a call or I believe its failing negotitation.

Any suggestion or feedback ?

[dwhitefo]

Make sure that on the VG224 you have the equivalent commands in the mgcp configuration to use NSE to switch to g711alaw.

mgcp modem passthrough voip mode nse

mgcp modem passthrough voip codec g711alaw

also under voice service voip add "fax protocol none"

Lastly, make you need to find out if the terminating modem is really answering.  You should see an offhook indication in the MGCP debugs.

[ankit.joshi]

Thanks,

I have configured it for MGCP as well.

But I am not sure about "fax protocol none" , if I configure it , wouldn't it affect normal fax calls processed by VG224.?

ATM when I dial fax number I can see OFFHOOK reqest

sh voice call summary
PORT           CODEC     VAD VTSP STATE            VPM STATE
============== ========= === ==================== ======================
2/0           g711ulaw   n  S_SETUP_REQ_PROC      FXSLS_WAIT_OFFHOOK 

cheers

[dwhitefo]

WAIT_OFFHOOK just means the phone is ringing.  If the modem is actually answering you should see a CONNECT state.