IMT Carrier Architecture > +1 (H.248)| | Device | GW1| ----> +1703, Control| | | | > +1202, [TG1] | | IMT | > +1 (SIP) | | | >| MGC | | GW2| ----> +1540, | | | | | | | > +1202, [TG1] | | | Call | | IMT Setup | | | | > +1 (SIP) | Routing | | | | | >| Proxy | | | GW3| ----> , | (LS) | | | | | > +44 | | | SS7 | | > TO PSTN | | | | PRI (B&D) | >| GW4| ----> | | (SIP) | MF > GW5| ---->

GWREG advertises the availability of _______ Gateway availability –MGC advertises its GWs availability –Smart GWs availability known directly Route availability ( ) –Are all MGC routes for +? Why express preference? –Also other address families (CIC, NP) Trunk group availability –Trunks associated with physical interfaces –CSI states (blocked locally/remotely, idle, etc) –Availability of routes predicated on trunk groups But often not on a single GW

Qualities of TGs Static Attributes Directionality Protocol used over trunk Reachable carrier(s) Reachable switch (PC/CLLI/LRN) Telephone number prefixes Total Capacity –Actually static? Dynamic Attributes Blocking state Current capacity