VG224 Modem Problems

[al.coutinho]

Folks.

I have a VG224 and a 2651XM as athe PSTN Gateway. The Gateway uses H323 with CCM 3.3(4 ) and it's connected to the PSTN using a R2 Digital E1 Trunk.

I can send and Receive fax but can't connect using a modem from the office to any other number ( like a remote access server or ISP dial-in number ). When I can connect the speed is usually 2400 ( only when it is set manually on the modem properties ).

Does anyone know what could be causing this problem and how to solve it?

Thanks.

[Maulik Shah]

- Is VG224 doing MGCP or H323? If mgcp make sure the line "mgcp modem passthrough voip mode nse" is in the config

- Are there any slips on the E1 line on the 2651?

- Make sure the inbound VoIP dial peer being matched on the 2651 has modem passthrough configured on it:

dial-peer voice xx voip

modem passthrough nse codec g711ulaw

The key is to ensure the right inbound dial peer is being matched on the 2651 - this link should help in seeing how inbound dial peers are matched:

http://www.cisco.com/en/US/tech/tk652/tk90/technologies_tech_note09186a008010fed1.shtml

[al.coutinho]

Thanks for the reply.

Do I need to configure the modem passthrough on the inbound dial peer? Isn't it to be configured on the outbound one since the problem I have is when someone using a modem from inside the office can't connect to any modem outside?

What is slips on the E1 line? The VG 224 uses MGCP and has this parameter configured.

Thanks again!!

[Maulik Shah]

First up for h323 / sip gateways there are always 2 dial peers matched for each call. One is the inbound and one is the outbound:

http://www.cisco.com/en/US/tech/tk652/tk90/technologies_tech_note09186a008010ae1c.shtml

http://www.cisco.com/en/US/tech/tk652/tk90/technologies_tech_note09186a0080147524.shtml

[al.coutinho]

Thanks again for the reply.

Follow the 2651XM configuration attached.

I tried to put the modem passthrough command you sent me on the Dial-peer voip 3 but didn't work...

Any Idea??

Follow the VG 224 Configuration attached as well.

Your help would be much appreciatted!!

Thanks!!

[Maulik Shah]

you should put it on the dial-peer voice 2 as that will be matched first on inbound

[al.coutinho]

I tried it before... It didn't work. What if I use the modem relay instead of modem passthrough?

[Maulik Shah]

that should work - modem relay is not supported on vg224 as far as I can see. So that is not an option.

[Jason Hendrix]

Maybe a little on the late side but... have a VG2951, VG224 CUCM 7.1.3 H323. Gas company calling inbound on DID line through VG224 and they could not connect did the changes to the port below and Gas compnay can now connect to modem, all the best.

conf t

voice-port 2/xx

shut

input gain 6 <-- normally at 0

output attenuation 10 <-- normally at 0

idle-voltage high

no shut

end

write memory

show run and look for port

!

voice-port 2/11

input gain 6

output attenuation 10

timeouts initial 60 <-- was already set to this

timeouts interdigit 60 <-- was already set to this

timeouts ringing infinity <-- was already set to this

description Gas Modem Line x143 <-- add a description for me

!

[Adam Loos]

Thanks Jason, used this for a fuel management system modem (Veeder Root TLS 350) and it worked!