Linksys ATA Administration Guide
66
SIP Trunking and Hunt Groups on the SPA8000
–
If
max
is less than
interval
, it represents the maximum number of times to cycle
through the hunt group. If max is 0, hunting continues indefinitely until the caller
either hangs up or the call is answered. Exceptions: This value is ignored if
algo = all
,
or
interval = *
(but it must be present and should be set to 1).
•
cfwd=target:
If the call is unanswered and the maximum hunting duration has been met, the
call is forwarded to the specified number. When forwarding the call, the SPA8000 sends a
302 response to the ITSP.
EXAMPLES:
•
1,2,3,4,5,6,7,8,hunt=re;*;1
Lines 1 through 8 are included (
1,2,3,4,5,6,7,8
). The hunt starts at the beginning of the list
(
hunt=re
). When an available line is found, the call stays with the line until the call is either
answered, rejected, or cancelled by the caller (
*
is entered for
interval
).
•
?,hunt=al;30;1,cfwd=14085550100
A wildcard character (
?
) is used to represent “all trunk lines.” All lines ring simultaneously
(
hunt=al
). If there is no answer after 30 seconds (
30
), the call is forwarded to the specified
number (
cfwd=14085550100)
.
•
?,hunt=ra;12;1,cfwd=14085550123
A wildcard character is used to represent “all trunk lines.” The Trunk UA chooses lines in
random order (
hunt=ra
). If a selected line does not answer within 12 seconds (
12
), the Trunk
UA chooses another line at random. If there is no answer after 1 cycle (
1
), the call is
forwarded to forwarded to the specified number (
cfwd=14085550123
).
•
?,hunt=ra;*;1,cfwd=14085550155
A wildcard character is used to represent “all trunk lines.” The Trunk UA chooses lines in
random order (
hunt=ra
). The interval is *, meaning the hunt stops when a selected line starts
ringing, and will ring the line until it answers, or the caller hangs up, or the line's ringer
times out. If the ringer times out, the call is automatically forwarded to the specified
number (
cfwd=14085550155
).
Outgoing Call Routing for a Trunk Group
Outbound calls on a trunk line are handled as follows:
1. When a PBX phone selects an outside line, the PBX looks for an open line. If the PBX finds an
open line, it takes the line off hook and bridges the audio between the PBX phone and the
line. On detecting the off hook signal, the SPA8000 Line UA plays dial tone and ready to
collect digits from the PBX phone.
2. As the PBX phone user dials the number, the Line UA applies its dial plan to the number. If
the Line UA detects an invalid number, it rejects the all by playing reorder tone, then
howling tone, then silence. If a valid number is received, it sends a SIP INVITE message to
the internal Proxy.
3. The Proxy routes the call to the trunk group UA for the line, and the trunk group UA will
attempt to place the call to the ITSP if there is available capacity on the trunk. If there is no
call capacity left on the trunk, the internal Proxy will reject the INVITE from the Line UA,
which in turn terminates the call and plays reorder tone out to the FXS port.
