| 摘要 |
A method for service transmission, a method for IP-based service transmission, it enables successfully to establish and transfer voice fax data service and the like on IP bearer, while it also can save the transmission bandwidth. In the present invention, the calling party and the called party pre- negotiate the service type and corresponding codec scheme before establishing the call, then after normally establishing the call, MGW always detects the signaling associated service during the calling, and reports to MGC, MGC determines the service type, and MGW switches to corresponding codec scheme. For the fax service or Modem service, determine whether it is high speed fax or Modem service according to the specific signaling, and based on G.711Red coding scheme bearing voice fax data service, after determining the high speed fax or Modem service, switch to T.38 codec scheme as more effective. The invention determines the service type according to V21 CM and the like within the band. |
