User guide

16 Release Notes for Cisco 2500 Series for Cisco IOS Release 12.0 T
New and Changed Information
Cisco Multipath Channel+ (CMPC+)
Cisco Multipath Channel+ (CMPC+) is Cisco's implementation of IBM's MPC+ feature. The
CMPC+ feature in Cisco IOS Release 12.0(3)T supports MPC+ features and protocols necessary to
support IP. CMPC+ enables High Performance Data Transfer (HPDT). It allows TCP/IP connections
to the host through Cisco Mainframe Channel Connection (CMCC) adapters, using either the
TCP/IP stack or the High Speed Access Services (HSAS) IP stack.
DistributedDirector
Cisco DistributedDirector provides dynamic, transparent, and scalable Internet traffic load
distribution between multiple topologically dispersed servers. DistributedDirector is the only global
Internet service scaling solution that utilizes Cisco Internetwork Operating System (Cisco IOS)
software and leverages routing table information in the network infrastructure to make “network
intelligent” load distribution decisions.
Using routing table intelligence in the network infrastructure, DistributedDirector transparently
redirects end user service requests to the closest responsive server, as determined by client-to-server
topological proximity and/or client-to-server response times, resulting in increased access
performance seen by the end user and reduced transmission costs.
For Cisco IOS Release 12.0(3)T, the functionality of DistributedDirector from 11.1 IA is migrated
to 12.0 T. Cisco DistributedDirector is only available as a special hardware/software bundle on the
Cisco 2501, 2502, and the 4700-M platforms.
DLSw+ Enhanced Load Balancing
In a network with multiple capable paths, the DLSw+ Load Balancing Enhancements feature
improves traffic load balancing between peers by distributing new circuits based on existing loads
and the desired ratio.
For each capable peer (peers that have the lowest or equal cost specified), the DLSw+ Load
Balancing feature calculates the difference between the desired and the actual ratio of circuits being
used on a peer. It detects the path that is underloaded in comparison to the other capable peers and
assigns new circuits to that path until the desired ratio is achieved.
DLSw+ Peer Clusters
The DLSw+ Peer Clusters feature reduces the explorer packet replication that typically occurs in a
large DLSw+ Peer Group design, where there are multiple routers connected to the same LAN.
The DLSw+ Peer Clusters feature associates DLSw+ peers (that are connected to the same LAN)
into logical groups. Once the multiple peers are defined in the same peer group cluster, the DLSw+
Border Peer recognizes that it does not have to forward explorers to more than one member within
the same peer group cluster.
DLSw+ RSVP Bandwidth Reservation
The DLSw+ RSVP Bandwidth Reservation feature allows DLSw+ to reserve network bandwidth for
the DLSw+ TCP connection between DLSw+ peers.
Although it has been possible in the past to reserve bandwidth for a particular existing DLSw+ peer
connection through the RSVP CLI support in Cisco IOS software, the CLI required prior knowledge
of the TCP ports for which the reservation was being made. Because DLSw+ uses one well-known
port and one randomly assigned port, the reservation could not be made until after the peer
connection was active.