[daip] Re: aips tvload

[Patrick P Murphy]

On Fri, 26 Aug 2005 13:39:23 -0500 (CDT), Farhad Zadeh
   <zadeh at northwestern.edu> said: 

> On Fri, 26 Aug 2005, Eric Greisen wrote:

>> Perhaps I don't understand -you are at home and the work computer is
>> trying to write to your home machine's screen?

> Yes

>> That would normally be slow.

> I know but it is much much slower than it used to be.  My new DSL
> cable runs about 1.4Mby/s download

Given what you're doing, the upload speed may also be relevant.  Most
DSL service in the US is asymmetric ("ADSL") with upload bandwidth often
limited to *much* less than download.  Also, latency is as much a factor
in determining "snappy" response as bandwidth; you can get an idea of
what the latency is via either the "ping" command, or just plain
watching the interactive performance in a ssh session from home to work
(e.g. sluggishness in having what you type echoed on screen).  Given the
AIPS TV protocol, I could easily see either of these factors (latency,
asymmetric bandwidth) contributing to a significant slowdown in remote
AIPS TV performance.

Nominally in this case (AIPS tasks on work system, XAS display running
locally, SSSIN socket connection between them), most of the bytes should
still be of the "download" variety.

> so it should be faster.

I've heard *many* complaints from people on my local Unix User's group
(www.chuug.org) about wide differences in advertised vs. actual
performance on the DSL service offered around here.  If you are getting
1.4 Megabytes/second in actual download speed on other applications,
then clearly the performance for remotely commanded AIPS TVs should be
better.

				- Pat (offering potentially irrelevant
                                      advice from the peanut gallery :-)