TCP/IP Limitation?

[Jorge Cocomess]

Greetings,

Is there a limitation on the OpenVMS 7.3-2 with number of TCP/IP connections? If so, where and how could I check out this??
Background:
About 200 client connect through the application runnning on OpenVMS, but before they can connect to this application they must first connected through a Windows 2000 server acting as a Cache server.

Thanks,
J

[Arch_Muthiah · Accepted solution]

Hi J,

I thing that there are no limitations on a server's ability to handle millions of TCP connections if memory resources are available to service the connections. If memory is insufficient, the server will reject new connections.

Google says 5 connections can be queued per port for FTP connections.


Archunan

[Andy Bustamante]

There are limits on the number of BG devices(raised with TCPIP 5.4). Which TCPIP product are you running?

Assuming TCPIP 5.4, shipped with 7.3-2 there is a default 9999 BG allowed. You can increase this manually or by loading the tcpip scalable kernel. See
http://h71000.www7.hp.com/doc/732FINAL/TCP_RN/tcp_rnpro.html#scalable_kernel

You can also manually raise ovms_unit_maximum with the sysconfig utility. See the TCPIP Tuning and Troubleshooting manual at http://h71000.www7.hp.com/doc/732final/6631/6631pro.html

Is there a specific performance issue?

Andy

[Jorge Cocomess]

Andy - No performance issues at the moment. We're seeing drop connections from the client server (W2K) - We have about 200 connections through this client server and then pass-thru the application server (VMS). And yes, we currently using Pathworks Advanced server with license for 200 units.

Thanks,
J

[David B Sneddon]

Jorge,

Exactly what type of connections are dropping?

Dave

[Jorge Cocomess]

Dave - That would be TCP/IP connections that are dropping - Sometime 2-7 drops during the day.

Thanks,
J

[David B Sneddon]

Jorge,

Yes, I guessed it would be TCPIP... :-)
Are the sessions telnet, ftp, connections to
pathworks shares?

Dave

[Jorge Cocomess]

Dave - It's not FTP session. So, I guess it would be telnet. I will wait later today or when some users connect through the client server, I'll run netstat -n to see their connections and let you know more on what type of connections they are.

Let's say it's telnet, is there any tweaks we can do?

Thanks,
J

[Jorge Cocomess]

Dave - After I ran netstat -n I see al lot of NetBios connections. Any ideas?

[Andy Bustamante]

Is this a case of having to reboot the Windows 2000 system to restore Pathworks connections? If you're running Pathworks 32 ver 7.4 on the client there is an updated DECDNP114.SYS available from HP which corrects this. If you check the Pathworks event log, look for:

Added 32 packets to the datalink buffer pool, total=xxx

After xxx hits 512, the Pathworks connections will hang.

Andy