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VG204 MGCP configuration


Hi       There

Could someone help me to configure the VG204 as MGCP fax gateway?

I configured the gateway which connect to our fax machine

I have configured the VG204 as MGCP fax gateway and it already registered to our call manager(version 7).

there are 2 questions

1 is when try to configure the Subunit, it asked to choose port type (POTS, loop start and ground start), I am not sure which one should I chose

2. I chose the port type as POTS and the gateway registered to the call manager sucessfully, but I can not make fax call

     if I try to ring from the fax machine after i dial the first number i will hear the busy tone

     if I ring from normal IP phone to the fax number which connected to the VG204, it keeps ringing and would not change to fax dialtone

I checked the cisco website and could not find any information about the configuration on the call manager

Thank you in advance


Gajanan Pande
Cisco Employee
Cisco Employee

If you want to connect any analog phone or FAX machine to that port, you must choose either loop start or ground start.


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To make a call from the fax machine, you need to apply the correct CSS under its directory number.

For the fax incoming call, can you please post your configuration on the VG204 ?

i guess it's a t38 protocol not applied under your dial-peers.

PS: you may need to check under the Fax menu, if it is set to auto-answer.

paolo bevilacqua
Hall of Fame Master Hall of Fame Master
Hall of Fame Master

Why MGCP? For fax ou should use H.323, or SIP. And for phones, SCCP.

Hi          Paolo

When I choose the protocol, it only have MGCP and SCCP for the VG204 gateway in the CUCM, could you show me where can I select the protocol as H323 or SIP

Thank you in advance


I found out it was my human error caused the problem

For the outbound problem, it was because i plug the cable in the wrong port, but if I choose ground start I could not hear the external dialtone, I have to use loop start to make it work

For the inbound problem, because before i add the VG, there was already an ATA associated with the number, when i dialed the number it went to the ATA

Sorry for the confuse caused by my stupid error

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