Should CIFs optimization work in both directions across a WAN?

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Jan 8th, 2009
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Assuming everything is configured correctly, should I be able to get CIFs optimization occurring on both the core WAE and remote WAE depending on which way files are being copied?

In other words, if I am at the remote site on my PC and copy a file from a Windows server at the datacenter to my PC, I get CIFs optimization on the remote WAE-522. Now if I am still at my remote PC and I copy a file from my PC to the server at the datacenter, should I get CIFs optimization on the datacenter core WAE?

Or is WAAS really designed to optimize CIFs only if the traffic is flowing from the datacenter to the remote site?

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dstolt Thu, 01/08/2009 - 11:14
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In WAAS 4.0, you recieved TCP optimizations and compression in both directions and CIFS optimizations from a "Core" WAE to an "Edge" WAE only.

In WAAS 4.1, you still get the TCP optimizations and compression, and by enabling the transparant CIFS AO, you receive bi-directional CIFS optimizations (no more core and edge), however as the CIFS cache has to be populated at both ends.

Hope that helps,


jkeeffe Thu, 01/08/2009 - 12:28
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Dan - would you please take a look at my previous post titled "CIFs cache on Core-7341 not working." where I describe a problem where the core 7342 does seem to be doing CIFs caching as shown by the 'sh statistics conn opt' command, but the GUI does shows the CIFs cache as having 0 bytes. I include screen shots.

jkeeffe Fri, 01/09/2009 - 10:59
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CIFs Caching not supported at the data center side in 4.1.1c. I just got this info from one of the TAC guys when I opened up a case. It was going to be included int the 4.1.1 release but it wasn't for some reason.

So CIFs caching is only support on the remote WAEs for transferring Windows files from the data center to the remote host.

At least DRE/TFO will work going the other way and hopeful Cisco will incorporate di-directional CIFs caching in a soon released version.

jzitcovi Mon, 02/09/2009 - 10:51
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Yes, in 4.1, bi-direction optimization for CIFS is available.

jkeeffe Tue, 02/10/2009 - 07:35
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I've heard both answers now - that b-direction CIFS optimization is available, and that it isn't. Here is the response I got from TAC:


From: Tom Jardin [mailto:[email protected]]

Sent: Friday, January 09, 2009 9:44 AM

To: Keeffe, Jim H

Subject: RE: SR 610444895 : WAE-7341 not showing CIFs cache entries in GUI.

Hi Jim,

What you are asking makes sense and we get this question frequently, but Uploads are not cached at the data center. There was some thought that this would be different in the 4.1 CIFS AO mode but not so.

The 7341 is showing the CIFS connection from the core. I assume the source IP is the client IP at the remote site?

I'm not sure why it works this way, but I understand it is just a limitation of WAAS.

You should see a good benefit of DRE/TFO when uploading files.

I hope this answers your questions.



From: Keeffe, Jim H [mailto:[email protected]]

Sent: Friday, January 09, 2009 12:27 PM

To: 'Tom Jardin'

Subject: RE: SR 610444895 : WAE-7341 not showing CIFs cache entries in GUI.

Hi Tom -

I understand it won't cache locally. But how about caching remotely - in this case on the WAE-7341, so

when the same user, or a different user, copies that same file across the WAN to the data center, it is

cached on the 7341 and doesn't have to traverse the WAN again?

Also the 7341 shows CIFs optimization - but is that because it is optimizing the CIFs traffic only from

the server to the remote PC?

I don't understand why it only works in one direction. Is that on purpose? We have huge files that

users regularly transfer from their remote PC's to the data center Winows filer and I was hoping that

WAAS CIFs caching would help in that area. Is the only option the DRE/TFO acceleration?

Thanks for answering my question so I can completely understand how CIFs caching is designed to work.

- Jim


So the BIG question is: What's the real answer? If bi-directional CIFS optimization is available, how does one implement it if it is not done automatically?

jzitcovi Tue, 02/10/2009 - 09:20
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In 4.0 or 4.1:

From the remote office:

1 You will see acceleration pulling a file from the datacenter over CIFS

2. You will see acceleration pushing a file to the data center over CIFs

From the data center:

1. You will see acceleration pushing a file to a server or desktop over CIFS

2. You will see acceleration pulling a file from a server or desktop over CIFS

You only need to enable the CIFS AO to see acceleration.

you can see the accelerated flow by

sho stat con opt


sho cifs session list

In 4.0 you needed to configure the connectivity directives to designate where the server was located. This is not longer needed in 4.1

WAE-EDGE#sho statistics connection opt

/* bi-direction acceleration example */

D:DRE,L:LZ,T:TCP Optimization,


ConnID Source IP:Port Dest IP:Port PeerID Accel

284232 00:14:5e:41:f0:6c TCDL

284238 00:14:5e:41:f0:6c TCDL

WAE-EDGE#sho ver

Cisco Wide Area Application Services Software (WAAS)

Copyright (c) 1999-2008 by Cisco Systems, Inc.

Cisco Wide Area Application Services Software Release 4.1.1


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