Cabletron Systems FRM User Manual - page 112
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Frame Relay Module 4. 0 User G uide, Rev 01
Search Order for Subscriber Addresses
A subscriber address that includes a wildcard potentially matches more addresses than
one with no wildcards. For example, the address
*
matches all other addresses.
Without a checking mechanism an address with no wildcards could be read as a match
for an address with a wildcard, and sent to the wrong place. To avoid this, a search
order has been established for performing call routing:
●
Addresses with no wildcards will be searched first.
●
Addresses with only
?
wildcards will be checked next.
●
Addresses with
*
will be checked last.
Within each wildcard group, addresses with the most non-wildcard digits will be
checked first. For example,
311012345678*
will be checked before
3110*
.
Hunt Group Example
Here is an example of how the hunt group function works, using the algorithm
Least
LCN With Thruput
. The routing path process will calculate a loading factor based on
the number of LCNs in use and the line speeds for each Call Request received. The
method is proprietary, but is described generally here.
Ports and letter symbols in the example are:
Line
Speed
RLP 0, port 0 2400 bps
RLP 1, port 0 4800 bps
RLP 1, port 1 in failed state, but is defined as a routing path
RLP 1, port 2 9600 bps
M
= The maximum bps of any operational line in this routing path group.
w
= The bps of an individual line.
U
= A proprietary line utilization factor, taking into account the number of
active VCs on the line, and the line's speed.
To illustrate how calls will be distributed among these lines, assume there are no calls
on any line. The lines will have the following process variables:
Line
Speed
M/w
U
0,0
2400
4
4
1,0
4800
2
2
1,1
failed
1,2
9600
1
1
A Call Request will be routed on line 1,2, since it has the lowest
U
. The next Call
Request will produce a new calculation for
U
for all lines, and will again be routed on
the lowest
U
line:
Line
U
0,0
4
1,0
2
1,1
failed
1,2
2