
DBL Technology Co., Ltd.
GoIP User Manual
www.dbltek.com
Technical Support: [email protected]
24
1.
Single Server Mode
In this mode, only one SIP registration is used for single or multiple-line operation. Please make sure that
your SIP server supports multiple-line operation and the SIP account is configured in the SIP server to match
the number of lines available in the device. Call routing to a GSM channel is now based on the Routing
Prefix of each GSM channel. Here is the channel selection algorithm.
a)
All Routing Prefixes are set
-
Try to match the number received for making an outgoing call against the Routing Prefix of each
channel. If only one match is found, the corresponding channel is used to make the outgoing
call. If more than one matches are found, the best available channel among the matched
channels is selected. If no match is found, the call is rejected by sending back a SIP 503
message.
b)
Only some Routing Prefixes are set
-
Try to match the number received for making an outgoing call against those Routing Prefixes
that are set. If only one match is found, the corresponding channel is used to make the
outgoing call. If more than one matches are found, the best available channel among the
matched channels is selected. If no match is found, an idle channel without a Routing Prefix is
used to make the call. Otherwise, the call is rejected by sending back a SIP 503 message.
c)
None of the Routing Prefixes are set
-
An idle channel is selected to dial out the call. If no idle channel is available, the call is rejected
by sending back a SIP 503 message.
It is important to note that the Routing Prefix (P) must be removed via the dial plan before the number is
dialed out. The dial plan syntax to remove the Routing Prefix is "P:-P|". Please refer to section 3.3.6 for
more information on the Call Out Dial Plan.