vpn and dual NIC router / load balancing

[NetTransplant]

I have a client that uses a patient database through VPN access to the local
hospital system.

The response times on images, 3d scans etc, is terrible. X-rays are fine.
I have recommended working with the hospital system to see why the images
are so slow but this doctor likes toys.

He wants to purchase a Cisco dual WAN router to connect to the two local
Internet systems, one DSL (4 M max), one Cable (5M max) and use load
balancing to increase performance.

My issues are one, whether the VPN application source supports this and two
calculating the maximum throughput that could be expected. The doc insists
he would get 9 m transfers, I think the load balance would provide far less.

The doc's office is just a pile of Win98 and WinXP workstations each in
their own
workgroup.

Comments?

 

[Phillip Windell]

My issues are one, whether the VPN application source supports this and two
calculating the maximum throughput that could be expected. The doc insists
he would get 9 m transfers, I think the load balance would provide far

less.

Assuming first that the "load balancing" doesn't break the VPN (good chance
it might),....DSL and "Cable" are asyncronous,...the upload speed is always
much slower than the download speed,...VPN will "sync" it's speed to be the
same in both directions,...therefore the VPN will always run at the slower
upload speed and not the faster download speed.

--
Phillip Windell [MCP, MVP, CCNA]
www.wandtv.com
-----------------------------------------------------
Understanding the ISA 2004 Access Rule Processing
http://www.isaserver.org/articles/ISA2004_AccessRules.html

Microsoft Internet Security & Acceleration Server: Guidance
http://www.microsoft.com/isaserver/techinfo/Guidance/2004.asp
http://www.microsoft.com/isaserver/techinfo/Guidance/2000.asp

Microsoft Internet Security & Acceleration Server: Partners
http://www.microsoft.com/isaserver/partners/default.asp
-----------------------------------------------------

 

[Neteng]

Load balancing will break the VPN. You will have to use a VPN load balancer,
which in this case will not do you any good because your trying to get a
bigger pipe, not truly load balance. Load balancing is sharing the load
across multiple devices, not necessarily internet connections. To load
balance across data lines, you need multiple private lines and a routing
protocol or if you want to load balance across internet connections, you
need BGP and an excellent engineer. He will NOT get 9MB with a load balanced
VPN, the technology does not work that way. I would do an eval and see what
the file sizes are, the frequency of push/pulls of images, xrays and the
sort, and you may be able to justify a private line or a DS-3.

My issues are one, whether the VPN application source supports this and two
calculating the maximum throughput that could be expected. The doc insists
he would get 9 m transfers, I think the load balance would provide far

less.

Assuming first that the "load balancing" doesn't break the VPN (good chance
it might),....DSL and "Cable" are asyncronous,...the upload speed is always
much slower than the download speed,...VPN will "sync" it's speed to be the
same in both directions,...therefore the VPN will always run at the slower
upload speed and not the faster download speed.

--
Phillip Windell [MCP, MVP, CCNA]
www.wandtv.com
-----------------------------------------------------
Understanding the ISA 2004 Access Rule Processing
http://www.isaserver.org/articles/ISA2004_AccessRules.html

Microsoft Internet Security & Acceleration Server: Guidance
http://www.microsoft.com/isaserver/techinfo/Guidance/2004.asp
http://www.microsoft.com/isaserver/techinfo/Guidance/2000.asp

Microsoft Internet Security & Acceleration Server: Partners
http://www.microsoft.com/isaserver/partners/default.asp