Call Flow In Dynamic Mode; Call Flow In Frf.11 Trunk Mode - 3Com MSR 50 Series Configuration Manual

2386 C 138: V FR C
HAPTER O
Call Flow in Dynamic
Mode
Call Flow in FRF.11 Trunk
Mode
ONFIGURATION
and voice by using FRF.11.
VoFR complies with.
Figure 693 Protocols and standards that VoFR complies with
Signaling
Q.931-like
recommendation
X.25
Link layer (frame relay)
Physical layer
The following shows the call flow in the dynamic mode:
1 The calling party picks up the phone. The voice interface card detects the off-hook
action, plays dial tones to the calling party, and waits for the calling party to dial a
number.
2 The calling party dials and the voice interface card collects and stores the dialed
digits, namely, the called number.
3 Upon the completion of dialing, the voice gateway matches the called number
against voice entities.
4 VoFR processes the call if a VoFR entity is matched. The processing method
depends on the call mode configured for the VoFR entity.
5 In the dynamic mode, signaling exchange occurs between the calling and called
sides until the call setup succeeds or fails. This process also involves voice codec
negotiation and bandwidth request. The FR-supported voice gateway on the
originating side requests the frame relay to establish a voice channel according to
the outbound interface of the VoFR entity, and the frame relay dynamically
allocates an FRF.11 sub-channel to the voice channel.
6 After the call setup is successful, both the calling and called parties can
communicate.
The call flow in the FRF.11 trunk mode differs from that in the dynamic mode. In
the FRF trunk mode, once a voice channel is set up, this channel remains until it is
manually cleared. An FRF.11 trunk call directly uses the established voice channel
and the FR-supported voice gateway on the originating side unnecessarily requests
the frame relay to establish any additional voice channel when the calling party
originates a call. Therefore, the PVC IDs and FRF.11 sub-channel IDs at both ends
of the trunk must be the same in the FRF.11 trunk mode.
Figure 693 shows the protocols and standards that
Voice
G.711A-law
G.711µ- law
G.723R53
G.723R63
G.729A
G.729R8
FRF.11