SDP Mail Archive: RE: SDP> Suggestions for discussion at SDP session next week

RE: SDP> Suggestions for discussion at SDP session next week

Caruso, Angelo (Angelo.Caruso@usa.xerox.com)
Fri, 15 May 1998 08:43:24 PDT

I believe that in practice this problem would rarely occur. Get Bulk is
appropriate during discovery operations but not generally necessary.
Besides, most implementations are still SNMP v1 and therefore don't use Get
Bulk anyway. The thought of inventing a brand new mechanism instead of SNMP
is preposterous. Can't we please stop reinventing the wheel here?

Thanks,
Angelo

-----Original Message-----
From: Harry Lewis [mailto:harryl@us.ibm.com]
Sent: Thursday, May 14, 1998 4:34 PM
To: sdp@pwg.org
Cc: jkm@underscore.com; robert.herriot@Eng.Sun.COM
Subject: Re: SDP> Suggestions for discussion at SDP session next week

Bob stated...

>The concern I have about SNMP is that a client's "get status" query could
>be
behind several GetBulk requests and thus not get processed fast enough >for
the
client to determine that the printer is alive but very busy.

This is one reason notifications are useful rather than polling.

Harry Lewis - IBM Printing Systems

owner-sdp@pwg.org on 05/14/98 01:43:48 PM
Please respond to owner-sdp@pwg.org
To: robert.herriot@Eng.Sun.COM, jkm@underscore.com
cc: sdp@pwg.org
Subject: Re: SDP> Suggestions for discussion at SDP session next week

In my solution, I assume that there is a port dedicated to returning printer
status only and it has higher priority for processing than the normal IPP
port or the SNMP port. I want to keep the probability of a reply near 100%
even when the printer is very busy with other network requests.

The concern I have about SNMP is that a client's "get status" query could be
behind
several GetBulk requests and thus not get processed fast enough for the
client
to
determine that the printer is alive but very busy.

Can an SNMP request have as good a guarantee of a quick response as a
dedicated port?

Also in my proposal, I assume that the data returned is in an IPP compatible
format.

Bob Herriot

At 08:15 PM 5/13/98 , Jay Martin wrote:
>Regarding solution "b":
>
>> b) the primary issue is being able to determine the printer status,
i.e.
>> did the connection fail because the printer is down or just busy.
One
>> simple solution is to have a printer read on a UDP port dedicated
to
>> returning a status summary whenever it receives a request on the
port. If
>> the incoming bytes are limited and have simple options, the
printer
will
>> never be tied up for long on each transaction and will always be
able to let
>> a client know if it is alive and whether there are any problems.
Then if the
>> connection fails, it is because the printer is down or the IP
address is bad.
>
>Sounds like a fixed SNMP query. Why don't we just use
>SNMP and the Printer MIB for this kind of thing?
>
> ...jay
>
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