13GPP TS 26.110 V5.0.0. Codec for circuit switched telephony service[S]. General Description, 2002.
2Camarillo G,Roach A,B Peterson J,L Ong. Integrated Services Digital Network (ISDN) User Part (ISUP) to Session Initiation Protocol (SIP) Mapping[S]. RFC 3398, Dec 2002.
