Re: Modem communication over FXS ports

wkreidy · ‎09-27-2001

I want to be able to use VoIP between two routers equipped with FXS ports to establish an asynchronous modem communication. I know that for Fax for example there's "fax-relay" feature. Any idea how to do this?

dgoodwin · ‎09-27-2001

"Modem passthrough" is supported on some gateway types however the support is limited, so it really depends on what type of gateways you are planning to use... which ones did you have in mind?

Also, expanded support for modem passthrough, as well as modem relay are anticipated for around the first quarter of 2002.

wkreidy · ‎10-01-2001

What are the gateways that support the "modem passthrough" and is there a special IOS version for this feature.

Where can I find some documentation on this.

Thanx a lot

cjsalas · ‎10-22-2001

We also need this kind of configuration. We have 2610's at the branch level and a 5300 at the HQ. We need to connect a modem to the FXS port on the 2610 and route out the call through the 5300 at the branch. I've seen and IOS for the 5300 that supports this but not for the 2610.

dgoodwin · ‎10-23-2001

Actually, modem passthrough is supported right now using:

AS5300 (H.323)

IAD2400 (MGCP)

Cat4224 (H.323,MGCP)

WS-X4604-GWY (H.323)

WS-X6608-T1/E1 (MGCP)

WS-X6624-FXS (MGCP)

DT-24+/DE-30+ (MGCP)

ICS-7750 MRP (H.323)

For many of the other platforms, including the 2600 and 3600, modem passthrough and modem relay are planned for a future release. To get more details on this you will need to contact your account rep.

qbui · ‎05-21-2003

David,

Modem relay is supported on 12.2.11T and I'm trying to test this feature on this code and 12.2.15T2. It doesn't seem to work. I have 2 3660s w/ FXSs. I only see MODEMPASS established and never see MODEMREALY. I follow the instruction on doc of 12.2.11T. Do you have any idea what could be wrong ?

Regards,

Hung

dumartin · ‎10-23-2001

Here is a link on fax relay. It goess over the config and what is needed to support it.

http://www.cisco.com/univercd/cc/td/doc/product/software/ios121/121newft/121t/121t3/dt_t38fx.htm

tboynton · ‎05-13-2002

The TAC just told me that MGCP was not supported on the 4224 for 2 months. I've been trying to get fax and modems to work on the 4224 using MGCP and haven't been able to get it to work.