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Outlook 2007 and 'fast networks'

Hi chaps,

Does anyone know what definition outlook users for a "fast network" ? We have some remote users who are seeing oddities which appear to be solved by ticking the "use http for fast networks" box in outlook.

These include where the user is on the same internal IP range as the remote servers (10.1.37.x etc), where the user is on cable broadband (20Mbps+ etc). In these instances, and some others, they seem to connect via TCP and fail.

I cant see anything on the web about exactly how "fast network" is defined, or changed.

1 Solution

If we don't select that option then it will try to connect on HTTPs only on slow network and on fast network it will try to connect on TCP... if we have configured the RPC over HTTPs..

For more details check this out:

stonnewayAuthor Commented:
oh yeah, but the question is what is a fast network in the eyes of Outlook?

is that 1mb, 2mb, 10mb, 100mb, 1000mb etc
BusbarSolutions ArchitectCommented:
fast network and slow network are based on TTL, replies, network speed and several factors, if outlook detects that network is fast which based on the above it will connect using TCP and that what causes the above issue
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stonnewayAuthor Commented:
But there has to be a definition somewhere surely? The definition of 'fast' for things like roaming profile connections can be set in a GP to take in to account fast connections between sites etc. Something similar must exist for Outlooks settings.
Hi, please see this..


However, i would think a "fast network" would be classified as a LAN (10mb+) which operates on a low latency (<1ms). What latency do you get when you ping the server?
Outlook defines any connection that is faster than 128kbps as a "fast network" as per:
so if your laptop users are setup for RPC/HTTPs then you can tick the "on fast networks connect using HTTP first" box to ensure no matter where they are (Internal or external) they will be connected over HTTP provided that connection doesn't take longer than 45 seconds to connect (but you can change the 45 second timeout as per the link I sent in my previous post)
Or if you really want them to connect using TCP/IP when in the office, increase the ConnectTimeout value from 45 seconds to 2 minutes or greater to give it enough time to try and connect.

BUT if I was you I'd just tick the "on fast networks..." box
Cause otherwise if they go home and plug into 100Mb hub or 54Mbps WLAN then Outlook thinks it is on a fast connection so will try TCP/IP first.

So ticking "on fast networks connect using HTTP first" is definitely the way to go as far as I am concerned.

Otherwise even if you found the registry/GPO setting to increase the 128kbps value, what would you increase it to to ensure clients at home (with 100Mb LAN or 54Mb WLAN) don't use TCP/IP?
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