Re: Proposal for two new objects

["Mark S. Lewis" <[e-mail]>]

>>>>> On Wed, 23 Feb 1994 13:11:50 -0500 (EST), Steven Waldbusser <[e-mail]> said:

>> 2.  Can vendor readily provide both the current and initial line
>> rates?  For example, Telebit modems can provide the current rate but
>> does not keep any historic info on rates.  So this would not be easy
>> for us as modem vendors.

> The requirements are:

> 1) The modem needs to know the initial line rate
> 	Every modem I've used has said: "Connect 14400..." or  "Connect 2400". 
> This seems easy.

> 2) You need to get it at the right time
> 	It's possible that there could be a problem in that the modem knows the
> initial line
> 	rate, but doesn't tell the management software, and/or the management software
> 	can't look continuously for the rate at connection startup.  But this
> won't be a problem if:
> 		a) the modem stores the initial rate for later retrieval
> 		b) the modem send the initial rate to the RCU or to the MS
> 		c) the RCU or MS is continuously polling and can see the initial rate
> 		   (e.g., in a connect message).

> 3)  You (may) need to store it
> 	If the MS/RCU can't get the initial rate on demand from the modem, it
> needs to store it
> 	locally.  This requires four bytes of memory.

> Did I miss something?

No.  I am saying Telebit modems do not store initial rate, and it must
be kept by the agent.  The difficulty is not the memory requirements,
it is the polling of the modem.  We would need to modify the agent to
send an in-band query of the current line rate immediately after the
call is established.

> Excerpts from modemmgt: 18-Feb-94 Re: Proposal for two new ob.. Mark S.
> [e-mail] (2251*)

>> Also, it might be more informative to keep the lowest rate rather than
>> the initial rate.  The current rate can be higher or lower than the
>> initial rate.

> Actually, in the application above, I'd be looking for the highest rate,
> and either the lowest rate or the current rate.  I rank them in this
> order:

> 1	initial + current
> 2	highest + current
> 3	initial + lowest
> 4	highest + lowest

> The reason that lowest is less attractive is that I don't know how long
> it was in that state.  In a week-long connection, 2 minutes spent at a
> very low rate is irrelevant, and might mask a couple of days at a
> higher, but non-optimal rate.


> Steve

Your point about short duration is significant.  It applies to all
data points: initial, lowest, highest and current.  The most
meaningful rate is that which is sustained for a long period.

I suggest we keep only the current rate and let management stations
poll at whatever frequency they think appropriate.  In this way, they
can get an idea of what line rates are being used over a long period.

... Mark

==========--------------       Mark S. Lewis      ----------==========
[e-mail]       Telebit Corp.      Voice [phone]