Nortel Networks NTRN10AN, 3500 Distributed multilink trunking, Bandwidth Reservation Protocol BRP

2-72Operation, administration, and maintenance (OAM) features

interfaces for data management, such as the Bay Command Console command line interface (BCC CLI) and Simple Network Management Protocol (SNMP).

Distributed multilink trunking

OPTera Metro 3500 supports network-to-network interface (NNI) redundancy through trunk groups. A trunk group is a logical group of two NNI ports in the same ring that are on separate 2xGigE circuit packs. Ports in a trunk group share traffic according to a hashing algorithm. In case of a failure on one port in a trunk group, all traffic is switched to the other port until the failure clears. Trunk groups enable redundancy between Resilient Packet Rings (RPR) by providing two NNI links between RPRs instead of one. The extra NNI link protects traffic between rings.

For more information, see:

•OPTera Packet Edge System Planning Guide, NTRN10YK

•OPTera Packet Edge System User Guide, NTN465YG

Bandwidth Reservation Protocol (BRP)

OPTera Packet Edge rings support a bandwidth reservation protocol (BRP) algorithm that allows you to provision a guaranteed bandwidth rate, called the reserved rate, for each node in the ring. The BRP algorithm attempts to provide access to the ring at or above the reserved rate of the node. The BRP algorithm works by sending credit packets from a source node to a downstream node when the source node is exceeding its reserved rate such that the downstream node cannot access the ring at its reserved rate. The credit packets are dropped by the downstream node, creating "holes" (gaps in the data stream) that allow the downsteam node to increase the rate at which it adds traffic to the ring. The source node sends enough credit packets to allow the downstream node to access the ring at or above its reserved rate.

For more information about OPTera Packet Edge services, see:

•OPTera Packet Edge System (Resilient Packet Ring) - Ethernet on page 2-62

•OPTera Packet Edge System Planning Guide, NTRN10YK

•OPTera Packet Edge System OPTera Metro 3000 User Guide, NTN465YG

1024 TDIs on a mapped UNI

You can have up to 1024 TDI values for each 2xGigE circuit pack and up to 256 TDI values for each port of the 4x100BT or 4x100FX circuit pack. You can configure up to 1024 TDI to VLAN ID mappings for each circuit pack. You must limit the number of mappings on each port of the 4x100BT or 4x100FX circuit pack to 256. On the 2xGigE circuit pack, there is no limit to the number of mappings on a port, as long as the total number of mappings on both ports does not exceed 1024.

OPTera Metro 3500 Multiservice Platform NTRN10AN Rel 12.1 Standard Iss 1 Apr 2004