front-end/back-end Exchange Server 1

[blombardi]

Is it necessary to have a front-end and a back-end Exchange server for a small company? What is the significance of the front-end and a back-end server?

 

[xmsre]

No, it's not necessary. The FE/BE design distribues load accross the two servers. The front end handles the SSL offload. You can asymmetcically scale a FE/BE design while preserving a single namespace; ie you can have one front end and multiple backends . You can load balance you front ends to provide further scalability.

The one thing that the design does offer a smaller org that doesn't need the scalability is what some would consider a more secure design. You can place the front end in the DMZ.

I see a lot of designs in mid sized companies where two front ends are load balanced, and an smtp connector exists on each. The backend is an A/P cluster with SCSI or FC attached storage. This design scales well, depending on storage, to about 7500 mailboxes.

You will want to note that unlike Exchange 2000, in Exchange 2003 the standard version can be a front end. This significantly reduces the software costs of implementing a front end server.