Enabling the R2 Protocol
November 2009 363
Channel Blocking
BSMI provides a mechanism for the Host application to block and
unblock individual channels as well as to receive indication that the
far end has blocked or unblocked a particular channel. Although the
R2 protocol remains “enabled”, a blocked channel is not available for
outbound or inbound calls. The BSMI message sequences for local
blocking and blocking by the network are illustrated in Figure 58.
Figure 58. Channel Blocking
(1) L4L3mCAS_CHAN_BLOCK
Host
(2) L3L4mCAS_CHAN_BLOCKED
Unblock a channel,
(3) L4L3mCAS_CHAN_BLOCK
(4) L3L4mCAS_CHAN_BLOCKED
Network blocks, unblocks a channel,
(3) L4L3mCAS_CHAN_BLOCK
(4) L3L4mCAS_CHAN_BLOCKED
Block a channel,