Fibre Channel SAN Extension over Optical Networks SONET/SDH Concepts
SONET/SDH Implementations
FCIP
FC over ATM
FC over SONET
There are several ways to use SONET/SDH to carry FC: Use FCIP to encapsulate FC in IP packets, and then run the IP over OC- x using packet-over-SONET/SDH (PoS). In this configuration, multiple layers of encapsulation add overhead and latency. However, nearly any combination of devices will support this architecture.
The FC-BB specification supports encapsulation of FC into ATM, and ATM can be carried over SONET/SDH. Encapsulating FC into ATM through an ATM Adaptation Layer (AAL) adds overhead and latency, as well as complexity of network operation and management.
FC can be encapsulated directly into SONET/SDH. Latency is reduced to the level induced by the SONET/SDH protocol overhead. This configuration can be suitable for synchronous applications. Several vendors have introduced support for FC interfaces in their SONET/SDH products.