VG224 Reliability Question

[jordan.bean]

We currently have about 20 analog fax lines. I'm trying to see who has had great success with the VG224 using T.38. Our gateways are currently MGCP that support T.38 and I understand the VG224 does the same. The only results that I find when Googling or looking here are people having problems. I'm looking for success stories of those that have implemented VG224's and T.38 for FAX.

[Nicholas Matthews]

This should work fine. Generally modem passthrough with NSEs is the easiest to configure, but T38 is a close second.

Here are the command you will need to run T38 depending on what protocol you use to control your VG224:

SIP/H323

dial-peer voice 1 voip / or voice service voip

fax protocol t38 ls-redundancy 0 hs-redundancy 0 fallback cisco

MGCP

mgcp package-capability fxr-package

mgcp default-package fxr-package

no mgcp fax t38 inhibit (default)

SCCP

Not supported

[jordan.bean]

Thanks. Would you say that with things properly configured you can achieve equally reliable FAX transmission as analog lines assuming the network/bandwidth is sufficient?

Also, any particular reason why you opted for CA based T.38 vs. letting the 2 gateways handle the negotiation?

[Nicholas Matthews]

Hi Jordan,

Generally once you get the configuration working, things go without problems. There are some corner cases that can be ugly, but that's not much different than any other technology.

You're correct on the CA controlled. It looks like I selected a different grouping of configuration that I expected.

Here's the NSE-based T.38 configuration:

SIP/H323

dial-peer voice 1 voip / or voice service voip

fax protocol t38 nse ls-redundancy 0 hs-redundancy 0 fallback cisco

MGCP

no mgcp fax t38 inhibit (default)

SCCP

voice service voip

fax protocol t38 nse ls-redundancy 0 hs-redundancy 0 fallback cisco ( starting in 12.4(11)T)