topic Re: Tuning TCP/IP INET parameter UDP_SENDSPACE in Operating System - OpenVMS

Tuning TCP/IP INET parameter UDP_SENDSPACE

Dima Bessonov — Tue, 26 Oct 2010 11:16:28 GMT

I am using HP TCP/IP V5.6 and V5.7 on OVMS IA64 V8.3-1H1 and V8.4. I need to increase the value of inet subsystem parameter udp_sendspace from 9216 (default value) to 42080 (equals to default value of udp_recvspace).

Question: are there any important relations between this parameter and other TCP/IP parameters? Should I change the values of any TCPIP and/or SYSGEN parameters appropriately?

"HP TCP/IP Services for OpenVMS Tuning & Troubleshooting" guide does not mention this parameter at all (although it does exist and is adjustable: "op=CRQ"), so I'd greatly appreciate advices from those in the know.

Dima

Re: Tuning TCP/IP INET parameter UDP_SENDSPACE

Jay So — Tue, 26 Oct 2010 23:52:14 GMT

Hi Dima,

I perused through the tuning guide, and unfortunately, yes, it is somewhat lacking...

1) udp_****space cannot exceed sb_max (sysconfig -q socket)
- same goes for tcp_****space

2) You should keep an eye on user quotas, and tune if needed - bytlim and pgflquota, especially.

3) Keep an eye on NPAGEDYN usage and tune if necessary

4) If you need further help and if you have a software support contract, it might be a good idea to call HP support.

Regards,

Jay So
OpenVMS Support Engineer
HP Technology Services - Global Competency Center
Hewlett-Packard Company

Re: Tuning TCP/IP INET parameter UDP_SENDSPACE

Dima Bessonov — Wed, 27 Oct 2010 20:31:49 GMT

Jay, thanks so much!

So far no need to change user quotas or NPAGEDYN. Generally, yes, it would be nice to have more specific formulas for calculating ADD_NPAGEDYN and increasing quotas, so I will try to open the request at the HP support.

Regards,
Dima

Re: Tuning TCP/IP INET parameter UDP_SENDSPACE

Dima Bessonov — Wed, 03 Nov 2010 16:04:35 GMT

To be communicated to HP via SA.