Ethernet and TCP/IP

[beth-martin]

Thoughts on whether Ethernet and TCP/IP too slow and unreliable for network-based storage?

TIA

Beth

[thomas.chen]

I would say no....In pre-Gigabit Ethernet days the answer to this question might have been yes; however, with full-duplex switching and Gigabit Ethernet speeds equaling that of Fibre Channel today, throughput is not an issue. TCP forms a connection between source and destination to ensure reliability with the inherent quality-of-service (QoS) and security benefits. User Datagram Protocol (UDP), with less overhead, doesn't have the reliability required for storage traffic

[jamiegraham]

This depends on the LAN configuration. To compete w/ Fibre Channel, a storage based iSCSI solution would have to be configured in a switched environment only. Also, the amount of payload carried in an FC frame vs. Ethernet frame is different (FC 2112 bytes, Ethernet ~1460 bytes). If you compare 1 Gb FC vs. 1Gb Ethernet, FC will always when.

[pleitnes]

How does the implementation of jumbo frames alter this? I would expect a dramatic improvement in throughput if you can push jumbo frames all the way from the iSCSI box to the iSCSI co-processor enabled server NIC.

[kthackwray]

I think that speed has less to do with the technology than the need for open standards (ever try connecting different SAN Fibre Channel device to each other ?)

Ethernet is shipping in 10GB/s ,fast enough?(FC is currently shipping 2GB/s type speeds) The biggest problem to overcome is the processing of the IP/Ethernet overhead (enter the Jumbo frames and TCP nic card offload) and next will be the marketing type problems (Brocade etc. may not be too happy to lose their piece of this pie). I think the Disk vendors will be pleased that they can connect to anyone .