Functional Components; Service Cross Connect Adapter (Cca) - Alcatel-Lucent 7750 SR Manual

Functional Components

Functional Components
The internal service cross connection feature uses a new adapter designed to fit within an IOM
(Input Output Module) MDA (Media Dependant Adapter) slot. One or more adapters are placed
into a cross connect aggregation group (CCAG). To cross connect two services, each service is
bound to the same cross connect aggregation group using the same cross connection identifier.
This section introduces each object and gives a brief explanation of its function.

Service Cross Connect Adapter (CCA)

The VSM Cross Connect Adapter (CCA) is a type of MDA for 7750 SR platforms designed to
provide an egress to ingress forwarding plane interconnection. When a CCA is installed in an
MDA slot, a set of virtual ports is available to the system providing the ability to extend packet
processing through an extra set of egress and ingress forwarding paths that CCA interfaces.
Unlike external port connections which utilize two TX-RX paths, a CCA interconnects the egress
forwarding path on the IOM directly to the ingress forwarding path. This eliminates the need for
the physical port MAC, PHY, cable and other MDA-specific components producing a less costly
and more reliable adapter. The complete 10G+ forwarding path is available allowing single
conversations up to 10G.
Bandwidth is utilized more efficiently than with externally cabled ports. Typically, the offered
load presented to each side of the cross-connect port-pair is asymmetric in nature. When physical
ports are used to cross connect services, each service is egress bandwidth-limited to the link speed
of the TX-RX path.
If one TX-RX path is under-utilized, egress services on the other path cannot make use of the
available bandwidth. Since the CCA is forwarding all services over the same path, all the available
bandwidth can be used.
The forwarding plane that the CCA interconnects maintains the complete egress and ingress
features of the services it is interconnecting. This includes the ability to remap QoS, enforce
policing and shaping, and provide ingress and egress accounting for each service.
Page 1432 7750 SR OS Services Guide