I have 2 gateways, one is a 2811 & the other is a 2911. The 2811 runs "advipservicesk9-mz.124-24.T3" and 2911 runs "universalk9-mz.SPA.151-4.M2" with IPBase,Security & UC. I have configured a fax machine on both the routers fxs ports. The routers are across a WAN and there is a gk in between. When I send a fax it fails and I noticed that the 2811 uses CISCO FAX CODEC & the 2911 uses T.38 CODEC. These are the default codecs for both the IOS. I am trying to configure the 2911 to use the cisco fax codec but, seems like the command is not supported anymore. The reason I want to use cisco fax protocol is because all the other routers on the network uses it thus is easier to change the NEW router that all the other older routers.
voice services voip
fax protocol cisco
Has anyone encountered this issue? Kindly share you experience or work around.