How many data-link connection identifier (DLCI)s can an interface support?
A. This question is similar to the question of how many PCs can you put on an Ethernet. In general, you can put a lot more than you should, given performance and availability constraints. When dimensioning a router in a large network, consider the following issues: • DLCI address space: With a 10-bit address, about 1000 DLCIs can be configured on a single physical link. Because certain DLCIs are reserved (vendor implementation-dependent), the maximum is about 1000. The range for Cisco Local Management Interface (LMI) is 16-1007. The range for American National Standards Institute and International Telecommunication Union Telecommunication Standardization Sector (ANSI/ITU-T) is 16-992. These DLCIs carry users’ data. • LMI status update: The LMI protocol requires that all permanent virtual circuit (PVC) status reports fit into a single packet and generally limits the number of DLCIs to less than 800, depending on the maximum transmission unit (MTU) size. This yields the following for a c
