Cabletron Systems 04-0053-01 Manual De Usuario

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SmartSwitch ATM User Guide   5-11
Virtual  Ports  and  Static  Connections
Soft PVC and PVP Connections  
Things To Watch Out For When Creating Virtual Ports
Make certain that the virtual port number (Base VPI) plus the VPIs designated by 
MaxVpiBits
 does 
not exceed the Available VPIs as specified by 
MaxVpiBits
 in the 
set portconfig
 command.
If you create more than one virtual port on a particular physical port, make certain that you do not 
run out of Available VPIs as specified by 
MaxVpiBits
 in the 
set portconfig
 command.
If you create more than one virtual port on a particular physical port, make certain that no overlap 
occurs among the VPIs used by the virtual ports.
Make sure the CAC policy is set correctly for the number of virtual ports.
Make certain that the traffic descriptors used by the virtual ports were created with the appropriate 
bandwidth and category of service.
Use the 
set cacserviceclassbw
 command (on a per-port basis) to allocate sufficient bandwidth to 
the specified service class
5.4
SOFT PVC AND PVP CONNECTIONS
The SmartSwitch 6500 supports both soft (or smart) PVC and soft PVP connections. Soft PVCs and PVPs are used to 
create PVC and PVP connections between ports on separate switches that are separated by a PNNI network. Normally, 
PVCs and PVPs must be configured manually from switch-to-switch across the network. However, soft PVCs and 
PVPs need to be configured only at the source and target switches. The connection is then routed through the PNNI 
network. Additionally, soft PVCs and PVPs take advantage of PNNI’s self-healing and crank-back capabilities. With 
conventional PVCs (for example), it a link goes down on the network, the PVC connection is broken. With soft PVCs, 
however, if a link goes down, PNNI has the capability of finding an alternate path to the target, thereby reestablishing 
the PVC connection.
Note
Soft PVPs are supported on the SmartSwitch 6500 ATM switch only.
Note
Only point-to-point soft PVCs and soft PVPs are currently supported.
5.4.1
Soft PVC and Soft PVP differences
The differences between soft PVCs and soft PVPs are essentially the same as those between standard PVC and PVP 
connections: 
Soft PVCs are identified by a VPI number and VCI number 
Soft PVPs use only the VPI (VPCI)
Soft PVPs must use a VPI > 0
Soft PVPs must be eventually terminated on virtual ports