HP StorageWorks 2/24 FW 07.00.00/HAFM SW 08.06.00 McDATA Products in a SAN Env - Page 164
of Electrical and Electronics Engineers IEEE 802.3x Ethernet flow, OSI Layer 4 transport.
![]() |
View all HP StorageWorks 2/24 manuals
Add to My Manuals
Save this manual to your list of manuals |
Page 164 highlights
Implementing SAN Internetworking Solutions 4 Router Connectivity through mFCP mFCP provides connectivity (through a GbE-bandwidth IRL) between two Eclipse 2640 SAN Routers. mFCP is similar to Fibre Channel protocol (FCP) but implements user datagram protocol (UDP) for open systems interconnection (OSI) Layer 4 transport. mFCP links are used for path failover in high-availability mSANs. NOTE: The Eclipse 1620 SAN Router does not support mFCP and must be deployed in mSANs as a single-router configuration. The UDP transport protocol is fast and easy to implement, but unlike transmission control protocol (TCP), UDP is connectionless, best-effort, and does not guarantee order or delivery of packets. UDP does not offer services such as packet reordering, retransmission of lost packets, or detection of duplicate packets. Therefore, only direct, high-reliability fiber-optic cable connections between SAN routers are supported. An mFCP link typically connects routers over short distances in a data center or campus. However, mFCP links can connect routers in a metropolitan area using wavelength division multiplexing (WDM) equipment or dark (unused) fiber. WDM and dark fiber are considered direct connections. SAN routers and the UDP over GbE connection support the Institute of Electrical and Electronics Engineers (IEEE) 802.3x Ethernet flow control standard. Flow control prevents buffers from overflowing and dropping packets. A UDP over GbE connection eliminates protocol overhead (eight bytes for UDP versus 20 bytes for TCP) and potential performance problems. The header is smaller and does not have windowing mechanisms that require resources to manage, and there is no buffering of segments until notification of receipt. The connection also uses 8B/10B bit-level encoding derived from Fibre Channel specifications, resulting in a low bit-error rate. Flow control, low overhead, and a low bit-error rate allow the mFCP connection to approach the reliability of a Fibre Channel connection. While a SAN router IRL is limited to GbE speed, multiple IRLs can be combined using IEEE 802.3AD link aggregation standard. Up to four links can be aggregated between two SAN routers. 4-20 McDATA Products in a SAN Environment - Planning Manual
![](/manual_guide/products/hewlettpackard-316095b21-fw-070000hafm-sw-080600-mcdata-products-san-environment-planning-manual-620000124500-2005-070bcff/164.png)