Comments on: Any problems with connecting 400+ telnet 5250 sessions through a WAN to a central server?

By: tomliotta

tomliotta — Tue, 20 Apr 2010 06:43:08 +0000

…when you type a character in a telnet session, it gets sent to the server and echoed back to the workstation. How much lag response is appropriate?

Just a minor comment on this — This is not true for TN5250 telnet sessions. Clients will transfer and receive entire screens in blocks. Communication is ‘block mode’. No characteras are sent to the host until an or other function key is pressed; then all characters that have been input are sent in a block transmission. A similar technology happens when screens are returned from the host. There is no ‘echo’ of individual characters.

For the question, 400 telnet sessions will probably never take as much bandwidth as downloading a single web page from this Techtarget site. I wouldn’t be concerned.

Tom

By: labnuke99

labnuke99 — Tue, 06 May 2008 13:28:22 +0000

I agree with Graybeard – your configuration should be adequate. You can put some priority queueing on the 5250 traffic but it likely will not add much performance to the link. Quality of Service (QOS) & Class of Service (COS) may be important also to keep this telnet traffic from being bandwidth starved by other traffic. However, this may be an additional upcharge by your carrier. You should be fine to begin with, but if you find sessions being slow and sluggish, consider adding QOS/COS to the link to carve out some dedicated bandwidth for your business application(s).

By: graybeard52

graybeard52 — Tue, 06 May 2008 00:58:35 +0000

fwiw,
We have 11 remote sites with varying numbers of 5250 sessions connecting back to a central site. Probably just about 400 sessions. We also have internet, intranet, VoIP, and GUI apps running across the same lines. We have bonded T1′s (2×1.5) at host site, remote vary from 512 to 1.5. The 5250 bandwidth doesn’t even show on the charts its is so small. If you have issues, it will the the other stuff.

By: genxsherpa

genxsherpa — Mon, 05 May 2008 21:38:06 +0000

Thanks for the feedback Labnuke.

To further explain our current configuration:

There are 23 remote sites with 20-40 5250 sessions each, all connecting back to a central AS400 using ‘thin client’ devices. Each location has a Full T1, while the host connection has a full DS3 all running through MPLS.

1) Other than the 5250 sessions, local Intranet, Internet access, and remote desktop connections will traverse the same connection. CoS will be implemented to allocate bandwidth priority to the 5250 sessions. All locations are within 150 miles of the host.

2) All print jobs will be spooled from the remote location to the host site. We have CoS implemented allocating bandwidth priority to the 5250 sessions and print jobs.

3) It is not likely that all 400 sessions will be firing at once, but that is dependent on the day. Located in a retail environment, weekends will provide the heaviest use of the terminals.

Thanks
Chad