Subject: Re: SDP> Suggestions for discussion at SDP session next week

From: Harry Lewis <[email-masked]>
Date: Thu, 14 May 1998 16:34:29 -0400

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

[email-masked] on 05/14/98 01:43:48 PM
Please respond to [email-masked]
To: [email-masked], [email-masked]
cc: [email-masked]
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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---

From: Robert Herriot <[email-masked]>
Date: Thu, 14 May 1998 14:13:57 -0700

Notification does not handle the case where a connection or a 'write' times 
out and the client (print server) want to determine if the printer is 
currently alive and making progress. The client (print server) needs to 
perform a "get printer status" operation immediately and not wait until some 
future notification arrives. The "get printer status" operation must give a
reply
(with a high probability) if the printer is alive.

Bob Herriot

At 01:34 PM 5/14/98 , Harry Lewis wrote:
>-