Faster firewalls and free jobstreams for MPE
December 15, 2015
We are trying to set up HP 3000 to HP 3000 communication via NS and FTP. The traffic is going through a firewall. We have it working, but the speed is too slow. We are getting 2-3 Mbps throughput on HP transfers. PC to PC transfers through the firewall are 22 Mbps. I checked that the LAN switch port on the 3000 is set to 100 - Full duplex.
I am being asked what are the the HP 3000 packet sizes or MTU. Where can I find and set the packet size?
Donna Hofmeister replies:
HP says, in the NMMGR Reference manual:
The Network Segment Size field specifies the largest packet (including all data, protocol headers, and link level headers) that will be sent by the LAN device. The only reason for entering a value smaller than 1514 is to make better use of memory for those systems where it is known that upper layer services will always send shorter messages. Note that whenever packets larger than the network segment size are sent, they will be fragmented to the network segment size, thus incurring fragmentation overhead at the source and assembly overhead at the destination node.
Default value: 1514 bytes
Range: 300–1514
What the above is not saying is that for most systems, setting this to anything other than 1514 will result in abysmal network performance. It’s much like a 100 megabit system acting like it's configured for 10 megabit -- because the system is busy fragmenting packets to fit into whatever number you've got.
On MPE, the tcp headers are stored in those 14 'extra' bytes. Regarding your tcp timers, click on the Allegro link here and react accordingly.
There used to be a CSL program that managed 3000 jobstreams. Now that there is the JOBQ parameter for MPE/iX, our site hasn't used that program in years. Maestro was the jobstream solution you paid for. What was that CSL program?
Connie Sellitto replies:
We used STREAMER from a CSL tape: It was customized for our company’s passwords, and allowed you to schedule a job for a different day, any time. It also allowed variable parameters.
I think most of these programs from the CSL were aimed at terminating jobs for various reasons.
Perhaps you meant MASTEROP, which is still available for free from our Allegro website. We didn’t write it, but its creator Carl Kemp kindly gave us permission to put it on our website. Additionally, there’s OCS Express, which we maintain.
Can I use a PC instead of a Console on A- or N-Class HP 3000s?
Gilles Schipper replies:
Sure you can, but ...
If you want to use the primary console port, you would need a serial port on your PC, along with an appropriate terminal emulator such as Reflection or Minisoft’s MS/92. Or, you could connect to hp3k via the built-in Secure Web Console port and TELNET. Only the very earliest versions of A/N-class models lacked a SWC port, perhaps only just the earliest A400 models.
Tracy Johnson adds:
We use a PC connected to the NIC on the GSP all the time. You may have noticed one of the RJ-45 ports is labelled "10-Base-T Console LAN". That's it. Of course you'll have to configure it at the Control-B menu.
For a LAN, the darn thing is slow at scrolling, too. It must be tied to the baud rate of the serial port.
We no longer use the serial port. Funny thing is they both echo the console at the same time. But only one at a time takes keyboard input. (You would have dueling operators at two keyboard vying for control.)
And if you want a LAN on your PC you'll need another NIC on it.