RE: Cross country point to point link question

[<Vinny_Abello () Dell com>]

Assuming you're doing FCoE or just iSCSI, you REALLY need to make sure your SAN vendor blesses something messing with 
packet headers on the SAN traffic. I don't think the caching mechanisms on the typical accelerator would help at all 
either. I somehow doubt they would support that unless they have their own solution. 

If you're just doing SMB or NFS or something similar then yes it would probably help overcome performance issues tied 
to latency quite a bit. But again, the magic is usually all tied to compression, TCP header modification and caching 
algorithms to local storage on each device.

-Vinny

-----Original Message-----
From: Petter Bruland [mailto:Petter.Bruland () allegiantair com] 
Sent: Thursday, April 18, 2013 12:20 PM
To: nanog () nanog org
Subject: Cross country point to point link question

Question for someone with some experience with long haul links (Las Vegas -- New Jersey)

[Cisco 4510 - SVI-VLAN x]---trunk---[Nexus5K LH optic]===fiber==={carriers across country}===fiber===[Nexus5K LH 
optic]---trunk---[Cisco 4510 - SVI-VLAN x]

We have two circuits, one that is the same vendor from east to west, and the other circuit is a two vendor deal. Both 
circuits are 1 Gbps with around 67-70 ms delay.

As soon as we had the links turned up, our SAN guy started complaining about poor throughput, asking us to throw in a 
couple of wan accelerators.
He was seeing a max throughput of around ~200 Mbps.

Question: For a long haul 1 Gbps link with 67-70 ms delay, would  installing a pair of wan accelerators make a big 
difference? 

Thanks,
-Petter Bruland