Cabletron Systems SmartCell 6A000 - Manual (Page 43)

SmartCell 6A000 User Guide 4-9
Switch Administration Setting Up Routes
IISP Metrics and Load Sharing
You can assign a metric value to each IISP route. The metric "weights" one route against another. The IISP metric
specifies which of two or more routes is used the most for setting up calls. Counters are set up for each route that equal
the route's metric. These counters are decremented as calls are set up through the routes. When a route's counter reaches
zero, that route is not used until all other router counts reach zero, and all router counters are reset to their metric value.
Obviously, the route with the lowest metric decrements to zero first and remains unused until all other routes also
decrement to zero.
For example, two parallel routes are set up for redundancy and for load sharing between two switches. One route (A)
has a metric of one, while the other route (B) has a metric of two. This means that for every call set up through A, two
calls are set up through B.
The exception to the example above occurs when one of the parallel routes uses more bytes of the ATM address to
define the route destination. If true, the path through the route with the longer destination address is always selected
first.
For example,
If routes A and B are parallel and are defined by
A = port A1, port address: 11:22:33, and metric 3
B = port B1, port address: 11:22:33:44:55, and metric 1
B is always favored for use over A and is used as often as possible, regardless of the fact that it has a smaller metric
than A.
SigConfig and PortAutoDetect with IISP Routing
The SmartCell 6A000 and the device to which it is connected must both use the same signaling type: UNI 3.0 or UNI
3.1. Use
modify sigconfig currentinterfacetype or defaultinterfacetype to set the interface type to match the
device on the other end of the connection. You also can use modify portautodetect to turn on auto detection of
signaling type, so the SmartCell 6A000 will sense the signaling type of the other device and use the same type.
IISP route signaling expects one end of the route to adopt user behavior and the other end to adopt network behavior.
However, some devices to which you connect your SmartCell 6A000 switch may be incapable of negotiating which is
network and which is user. If a device is unable to negotiate, use the
currentinterfacerole or
defaultinterfacerole parameter of the modify sigconfig command to set the port on the switch to the behavior
opposite to that of the connected device.
4.3.2 UNI Routes
Use static UNI routes when a device being connected to the SmartCell 6A000 switch either does not support ILMI or
whose implementation of ILMI is incompatible with the SmartCell 6A000.
Use the add uniroute command to add static routes to the UNI route table of the switch.
For example, to add to port A1 a static UNI Route that connects to a device with ATM address
44:00:00:00:00:00:00:00:00:00:14:41:80:00:30:E5:14:41:80:00, enter the following:
SmartCell ZX # add uniroute
PortNumber(A1) :
UNIATMAddress() : 44:00:00:00:00:00:00:00:00:00:14:41:80:00:30:E5:14:41:80:00
SmartCell ZX #