Exchange Client Caching problem

Panzer919

Let me preface this question by stating upfront that I am not an Exchange admin, I am the Network Engineer for my org and we have an issue that baffles our admin.

We have 12 remote sites over MPLS and their links are 2Mb/s. We are currently using email caching and when someone starts to cache their inbox's it chokes the bandwidth. I thought about putting a policy in place to limit this but it would cause the same thing to happen if someone starts caching.

Is there any way to limit the bandwidth used by caching on either the client or server?

I brought up only downloading headers and mailbox size limitations but this is a law office and they all started throwing a hissy fit over the idea of not having all their emails.

Any information would help at this point.

Thanks in advance

Turgon

Panzer919 wrote: »

Let me preface this question by stating upfront that I am not an Exchange admin, I am the Network Engineer for my org and we have an issue that baffles our admin.

We have 12 remote sites over MPLS and their links are 2Mb/s. We are currently using email caching and when someone starts to cache their inbox's it chokes the bandwidth. I thought about putting a policy in place to limit this but it would cause the same thing to happen if someone starts caching.

Is there any way to limit the bandwidth used by caching on either the client or server?

I brought up only downloading headers and mailbox size limitations but this is a law office and they all started throwing a hissy fit over the idea of not having all their emails.

Any information would help at this point.

Thanks in advance

How about some QoS. Put the smtp traffic in a low queue. You get bandwidth issues then the email is slow but the rest gets through.

Panzer919

Turgon wrote: »

How about some QoS. Put the smtp traffic in a low queue. You get bandwidth issues then the email is slow but the rest gets through.

I thought about that, which was my first answer. The issue is our lawyers start literally screaming if they start seeing email delays. Thats one of the reasons why this has come up, people start caching their mailboxes and suddenly there are email delays and we start getting calls about it. The goal is to limit the traffic from a caching machine, which is why I thought of asking (after googling and looking on MS website) if there was a setting or regedit that could be used to limit this.

I wish caching used a different port number so I could separate the traffic but it doesn't.

Claymoore

What version of Exchange and Outlook are you using?

Panzer919

Exchange 2007 sp1, rollup 7
Exchange 2003 sp2

Outlook 2003 (sp3) and 2007 (sp2)

Claymoore

Get rid of Exchange 2003 and Outlook 2003. When used together, Outlook 2007 and Exchange 2007 allow for partial item synchronization to reduce the amount of data downloaded from the server. To be honest, I'm not sure it's going to help that much though.

Some of the perceived slowness may be due to the large mailboxes and large item counts in the primary folders bogging everything down. Exchange/Outlook 2003 are especially bad about this, 2007 is better, but the architecture in Exchange/Outlook 2010 are best for this.

Exchange 2007 also introduced a back-off request to throttle back a user performing a high number of RPC operations against a mailbox server. The back off request will slow down the rate of requests, slowing down one client to preserve overall performance for everyone else. Of course if it's slowing down the managing partner, you're still going to hear about it.

Those suggestions will probably only bring incremental improvements. I know it's not always the solution, but in this case I would recommend throwing bandwidth at the problem. When you centralize services, you need to keep clients highly connected. 2Mbps isn't highly connected. Going to 10 or 25 Mpbs connections probably wouldn't cost too much and would stop a lot of complaining.

Panzer919

Claymoore wrote: »

Get rid of Exchange 2003 and Outlook 2003. When used together, Outlook 2007 and Exchange 2007 allow for partial item synchronization to reduce the amount of data downloaded from the server. To be honest, I'm not sure it's going to help that much though.

Some of the perceived slowness may be due to the large mailboxes and large item counts in the primary folders bogging everything down. Exchange/Outlook 2003 are especially bad about this, 2007 is better, but the architecture in Exchange/Outlook 2010 are best for this.

Exchange 2007 also introduced a back-off request to throttle back a user performing a high number of RPC operations against a mailbox server. The back off request will slow down the rate of requests, slowing down one client to preserve overall performance for everyone else. Of course if it's slowing down the managing partner, you're still going to hear about it.

Those suggestions will probably only bring incremental improvements. I know it's not always the solution, but in this case I would recommend throwing bandwidth at the problem. When you centralize services, you need to keep clients highly connected. 2Mbps isn't highly connected. Going to 10 or 25 Mpbs connections probably wouldn't cost too much and would stop a lot of complaining.

Thanks for that, I kinda figured I'm in a catch 22 with this, but with me knowing almost nothing about exchange I figured it couldn't hurt to reach out and see if there was something I could do other than lowering the priority across the board.

We all know the reason its slow is because of the caching, most these attorneys refuse to delete any emails and since they are on the committee that decides IT policies, no one is allowed to limit or archive any of their email off.

I agree with upping our MPLS to 10Mbps but like most companies, if it runs mostly ok on 2 then they don't see justification in it. I figured I wouldn't rock that boat too much since I already got both our internet connections upped to 20Mb and our interconnect upped to 40.