This shouldn't be a problem. Set the outgoing GW as the SIP proxy server in your ATA, and disable SIP registration. Whatever you dial will go to the GW. Enable SIP on the GW and add a default dial peer to route all calls to the PSTN. Configure G.711 ...
SS7 in your network will increace the managebility of your network greatly. you will be able to control all AS5300;s from one central node, and do more advanced routing and white listing. (among other things)Have a look at the MGC, VSC3000 / PGW2200 ...
You log the messages to a windows machine running 'prserv.exe'. have a look at the 'prserv.txt' file included in the SIP ATA ZIP file downloaded from CCO for more instructions.(http://www.cisco.com/cgi-bin/tablebuild.pl/ata186) //thomas
You probably have to make sure that QoS is supported by your hardware. Then the packets will be filtered / selected in fast switching mode, and the delay is not noticeble. On a normal router you probably lower the maximum throughput of the router. //...