dcoluzzi
asked on
Exchange 2003 WAN Architecture
I work for a place that does a very high volume of email and we have 5 remote sites and a total of about 3000 users. All the remote sites, use a DS3 (45mbit) WAN link and the farthest site is about 2200 miles cross country and has a latency of about 55ms. On those links, there is usually a steady stream of HTTP traffic that is around 10mbit. At the moment our mailboxes are HUGE. Some get up to almost 10GB. We are opening a new datacenter soon and we are uncertain if we should make 1 large Exchange cluster there or make smaller ones at each of the sites. I know some companies are much larger and use a datacenter to centralize their email but I am unsure just how they do it. All of the clients are Outlook 2003 as well but cached mode is not an option for us and it conflicts with some of our apps. Some suggestions or links to whitepapers would be quite useful. Thanks!
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RPC over HTTP(s) is kind of a replacement for accessing Outlook via VPN. The reason being that a lot of companies block IPSec traffic at different levels, HTTP(s) is accepted. Granted, some organizations use packet shapers and will actually block RPC over HTTP(s). So, while it can help over WAN links, it is not likely part of this equation.
You may want to talk to the folks @ Veritas regarding Veritas VCS and Veritas VVR for remote site failover (if you decide to do that).
Most of us would be on the fence, too.
In that particular situation, one where Cached Exchange mode could not be used and where you could afford to maintain a local KVS server and the infrastructure it requires, it would make sense to have an Exchange server for the performance. Granted, you are talking more servers, more heat, more infrastructure, remote support, etc.
The upside:
You could keep everyone in one Admin Group and one Routing Group since you have some good link speed and good bandwidth. Once the cached Exchange Mode issues are resolved you could then start to centralize your infrastructure in places where it made sense to do so.
you could always start out with a pilot of users over the wire and users on-site. If the experience for the user (your customer) is near identical, then you would have a base from which to start. If, however, the experience was drastically different, then you would have a good reason to stay decentralized. I am sure you have heard the rest (multiple stores, meeting SLAs, etc.)
Again, once the cached Exchange Mode issues are resolved you could then start to centralize your infrastructure in places where it made sense to do so.
After the first Cached Exchange mode download, for non-roaming users, it really is a great application. Granted, I would not want to be the person waiting on the 10GB mailbox to synch over the wire. I also would not want to be the person that talks him/her into dropping into a .pst and then having the drive crash 2 months later.
In that particular situation, one where Cached Exchange mode could not be used and where you could afford to maintain a local KVS server and the infrastructure it requires, it would make sense to have an Exchange server for the performance. Granted, you are talking more servers, more heat, more infrastructure, remote support, etc.
The upside:
You could keep everyone in one Admin Group and one Routing Group since you have some good link speed and good bandwidth. Once the cached Exchange Mode issues are resolved you could then start to centralize your infrastructure in places where it made sense to do so.
you could always start out with a pilot of users over the wire and users on-site. If the experience for the user (your customer) is near identical, then you would have a base from which to start. If, however, the experience was drastically different, then you would have a good reason to stay decentralized. I am sure you have heard the rest (multiple stores, meeting SLAs, etc.)
Again, once the cached Exchange Mode issues are resolved you could then start to centralize your infrastructure in places where it made sense to do so.
After the first Cached Exchange mode download, for non-roaming users, it really is a great application. Granted, I would not want to be the person waiting on the 10GB mailbox to synch over the wire. I also would not want to be the person that talks him/her into dropping into a .pst and then having the drive crash 2 months later.
ASKER
One of the main problems is that they are all roaming users with the exception of a few. The roaming profiles are necessary in the environment or the workload would double. Once we get KVS fully implemented the mailbox sizes should drop drastically. I am assuming that centralizing was not really possible with Exchange 2000 and it was cached mode that really made the difference?
Yikes! That would definitely not be fun.
Ever considered Citrix?
I have centralized with Exchange 5.5 and Exchange 2000...cached mode just made it easier on the users (and the admins). There are some issues with cached mode and the global address list...but that does not discourage many folks. Granted, rebuilding the OST would not be fun for that 10GB mailbox...and synching it is not an option.
Ever considered Citrix?
I have centralized with Exchange 5.5 and Exchange 2000...cached mode just made it easier on the users (and the admins). There are some issues with cached mode and the global address list...but that does not discourage many folks. Granted, rebuilding the OST would not be fun for that 10GB mailbox...and synching it is not an option.
ASKER