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Primary to Basic Rate ISDN Multiplexer
TECHNICAL: 0118 931 2233
For primary rate interfaces the range is 0-30 for E1 and 0-23 for T1. For basic rate interfaces,
the range is 0-2.
e.g. if the number of channels for PRI 2 is set to 6 then b1-b6 can be used for calls provided
they are not assigned to semi-permanent connections.
The values in Channel Setup should meet the following formula to ensure that there are
enough channels on PRI 1 for all the calls that can be made. For simplicity, this formula
assumes no semi-permanent connections are set up on channels enabled for calls.
( no. of BRI channels enabled )
+ (no. of channels enabled on PRI 2)
≤
(no. of channels enabled on PRI 1)
Calls on hold release the b channel on the BRI if there is a spare channel on PRI 1 or it is the
first call on hold with b channel reserve on (always on for ETSI protoco1). This ensures that
calls on hold do not prevent other BRI's from having access to 2 b channels on PRI 1.
NB: the b channel is not released if Routing Mode is set to channel.
The number of spare channels on PRI 1 is
(no. of channels enabled on PRI 1)
- ( no. of BRI channels enabled )
- (no. of channels enabled on PRI 2)
Connection Set-up
This option brings up menus that allow semi-permanent connections to be set up. Use the
cursor keys and <ENTER> to select either PRI 1 or PRI 2 and then use the cursor keys to
select the timeslot to be set up. Use <SPACE> to cycle through 1 channel at a time. Use <#>
to cycle through 1 port at a time. Use <BACKSPACE> to set to unallocated.
Connections can be made between PRI 1 and PRI 2 or any BRI. This is to allow leased line
connections to be set up.
Connections can also be made between PRI 2 and any BRI. This is to allow a router to be
connected.
The timeslot on PRI 2 assigned to the d channel (16 for E1, 24 for T1) can be can be assigned
a semi-permanent connection. If this is done no calls can be made on PRI 2.
If a connection clashes with another connection a '#' is displayed and the connection must be
changed before another connection can be modified or the menu exited.
Changes to the connections have no affect until escape is pressed to exit the connection
menu.