Toll free connection.... please help me


I’ve 1 asterisk server with 2 SIP trunks connecting to 2 different sites.

i.e, SiteA PSTN>SIP GW1>Asterisk>GW2>SiteB PSTN

I’m trying to establishing a toll free connection between SiteA and SiteB. When i try to place a call from SiteA to SiteB, it seems that Asterisk is connecting properly (between GW1,Asterisk & Asterisk,GW2). I get a 183 Session progress message and i can hear a ring tone but the phone at SiteB does not ring or connect. Can anyone advise me what else i should check?
Is this a valid setup? Any advice is greatly appreciated.

hi, in case anyone is facing a similar problem. I was using a Cisco2811 as one of the gateway and the problem was resolved after an IOS upgrade from 12.4(15) to 12.4(18 ) :smile: