VPN or Terminal Services

[Wanabe]

Currently I work for a company that consists of a single corp. office and has 4 branch offices spread out over a single metro area. The corp. office houses the servers/apps that are used company wide.

Currently, any apps that are used by the branch offices are accessed through MS Terminal Services. This seems to work well considereing that most of our branch offices have T1 data service. However, I'm considering the implementation of a VPN that would tie all of our branch offices together with corp. If this is done, can we expect as good or better response time with our apps that are accessed remotely? In other words, if I bring up a VPN between sites, and users no longer use Terminal Services to access our apps remotley, but instead, simply have a shortcut on their desktop which maps to our server apps at corp, what can I expect to happen with the response time of these apps in terms of latency? Is there more overhead with a VPN vs. Terminal Services? I currently have encryption set to Medium on our Terminal Server.

Thanks for any input.

Wanabe

[mbossman2]

it depends (the ever popular answer).

There are several things that affect the overall performance of a VPN connection. Some you can control, the big one you can't.

Things that you can control:

Encryption/decryption - if you use a dedicated hardware device that does the encryption in hardware, you will have a faster response as compared to a straight software solution...so the net gain here is to the VPN

Bandwidth allocation - depending on how you purchased your T1 and the service level agreements (SLA's) and committed information rates (CIR's) you may or may not be faster with the VPN. Don't have enough information to make that call.

Things outside of your control:

Overall latency of the internet. Sometimes the internet can get jammed up with higher than normal traffic amounts and if you currently using the internet to as your transport for your terminal services you will not see much, if any impact in performance. If on the other hand you are migrating from a private WAN, then you more than likely will see an impact from time to time.

Even if you are using the internet for access via terminal servers, there is a big reason to move to VPN:
the ability to work from home via the VPN is available via software clients loadable on home workstations

[Wanabe]

Thanks mbossman2. I think I'll just have to set up the VPN between a couple of our sites to see how things are truely going to work.

Wanabe

[fudtone]

Historically VPN is slow. Its good for end users but for "serving" I would stick with the terminal server.

[wedor]

You can work from home on a TS as well, it will work with most OS'es.

I can see no advantage of a VPN in your case, moving the apps to individual systems adds the amount of work needed to maintain the network. Newer systems capable of supporting the apps need to be purchased configured and installed.

Using the TS they have all the data/apps in one place, just about any system can be used as a terminal.

[mbossman2]

Originally Posted by fudtone Historically VPN is slow. Its good for end users but for "serving" I would stick with the terminal server.

it is all dependent upon your equipment. A software driven VPN takes a 30-70 % hit in performance whereas a dedicated hardware driven VPN has almost no impact on performance at all.

You pay your money and you get what you get: be cheap and get crappy performance, spend the money and you get performance that rivals a private WAN link.