Slow LAT connections

[Stanley F Quayle]

Hello. I usually lurk in OpenVMS space, but now I have a Tru64 client.

He reports that LAT is "slow", but all other network protocols (DECnet, TCP/IP) all work just fine.

What should I look for, short of capturing the packets on the network? The systems he's testing are all connected via a hub, so it would appear not to be a hardware issue.

[Vladimir Fabecic]

Please post output of:
# latcp -d
# latcp -d -C
# latcp -d -N
He reports that LAT is "slow" ???
Please explain that.

[Pieter 't Hart]

strange ..
we experienced this the other way around when migrating from LAT to telnet.
thing to check is the client software wich does or doesn't try to combine typed characters into a single packet.
It may even wait for a CR typed before sending the data to the host.

In combination with remote echo of typed characters, response may look slow.
(lat typically expects an echo from the host before putting the character on screen)
in this case activating local echo may improve the users experience.

[Stanley F Quayle]

I have more detail on "slow". It appears that LAT is buffering characters. When they eventually appear, they are in 500+ byte chunks.

Is there any affect to affect this behavior?

[Stanley F Quayle]

Here's the output:

latcp -d

Node name: GIXS1A
Multicast timer: 60 seconds
LAT version: 5 ECO: 2
Outgoing Port Groups: 0

Selected Interface Name(s): tu0
LAT Protocol is active
Agent Status: Disabled
Maximum Number of Learned Services: 100


Service information
Service name: DEV_TEST
Service ID: Digital UNIX Version V4.0 LAT SERVICE
Rating: Dynamic 115
Groups: 0

Service information
Service name: GIXS1A
Service ID: Digital UNIX Version V4.0 LAT SERVICE
Rating: Dynamic 115
Groups: 0

% latcp -d -C
No virtual circuits established.
% latcp -d -N
LATCP Node Counters
480 Seconds since last reset 0 Fwd out-of-seq
messages
98 Run messages received 0 Retransmitted
messages
59 Run messages transmitted 0 Bad circuit messages
56 Slots received 0 Bad circuit slots
60 Slots transmitted 0 Accepted
host-initiated
189 Bytes received 0 Rejected
host-initiated
42 Duplicate messages 0 Multiple nodes seen

LATCP Node Statistics
1 Circuits created 0 Circuit timeouts
1 Sessions created 9 Service messages
xmit
3825 Frames received 3724 Service messages
recv
69 Frames transmitted 3724 Service messages
used
0 Illegal frames

LATCP Node Errors
0 Circuit Start 0 HIC Solicit
0 Circuit Run 0 HIC Response
0 Circuit Halt 0 HIC Command
0 Service Anouncement 0 HIC Status
0 Other Message

%

[Vladimir Fabecic]

What is the "speed" of NIC?
10BaseT or 100BaseT?

[Pieter 't Hart]

from what to where is the lat session?
unix-unix unix-vms pc-unix?
can you try if different connections behave differently?

you mention "tru64 client" wich suggests connections outgoing from this server.
is that so?

[Stanley F Quayle]

This is actually running under CHARON-AXP, which emulates an AlphaServer 4000, 512 MB of RAM. The emulated network interface is a DE500 (DE435 wasn't supported by Tru64 for some reason). More details at http://www.stanq.com/charon-alpha.html BTW.

They've tried 10 Mb/s half, 100 Mb/s full, and Gigabit on the physical interface without any difference -- the emulator hides that, so I didn't expect it to change anything.

I'll have to reserch their network connectivity and what kind of devices they are talking to.

As for "client", I meant the customer.

[Vladimir Fabecic]

Have no experience with TRU64 running under CHARON-AXP.
Had problems only with 10 MBit NICs with alpha servers, but only because they were too slow.
The problem can be both CHARON-AXP or TRU64 related.
What patch kit you have?

[Pieter 't Hart]

have some experiece with charon-VAX (not AXP). But we never used it with LAT.
When using a 100Mbit network card charon-VAX gives a warning the card can pass more data than the emulator can handle.
our license expired feb. this year so i cannot experiment anymore.

LAT is a protocol that uses short timing.
Do you share the card between the host-os and the emulator? Then communication may improve if you add a second card and dedicate this to charon-axp.