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Re: (ASCEND) 32HDLC card



On Tue, Sep 16, 1997 at 01:14:41PM -0700, Kevin Smith wrote:
> At 01:14 PM 9/16/97 -0400, Phillip Vandry wrote:
> >> I've got a 32HDLC card...  I can't remember what it does :)  It's been
> >> sitting on the shelf so long in the bag that I can't remember why we
> >> bought it.
> >> 
> >> Umm, what's it for? :)
> >
> >I think it's to add more virtual channels on a Max.
> >
> >The MAX uses an HDLC channel for every connection. You can see how many of
> >them you have available by typing "sh if stat" in the termserver. They
> >are numbered wan0 through wan<whatever> (They are the interfaces).
> 
> No, modem connections do not use up an HDLC channel - only sync port
> connections
> do, like ISDN-PPP, Frame-Relay, ISDN-MP etc.
> 
> >If you have fewer of them than you have physical ports (channels, modems,
> >serial ports, etc..) then you are in trouble.
> 
> Since the MAX40xx can have up to 4*30 (Europe) channels = 120, and the base
> unit
> has 64 channels "built in", you might need to add more 32HDLC cards to support
> more than 64 simultaneous HDLC sessions (1 frame-relay port T1/E1 can use
> up 24/30
> in one go)....

Even more surprising: If you use a Max E1 (PRI) port as a leased line to
connect another Max or any other device which can do PPP on an E1, this
eats up 31 HDLC processors for _one_ line. Now guess how fast you are out
of HDLC channels ;)

The behavior of a Max which is out of HDLC channels is really interesting.
It will take all calls and will drop them whenever they are determined to
be framed and no framed channel can be established. The only indication
of the problem is a hard to interpret message in the debug mode saying that
during channel routing an additional ETHERDATA card was not found.

You ever asked yourself what the Etherdata slot actually contains ? It's
the onboard 64 HDLC processor unit. Every other 32HDLC module installed
in a slot appears as another Etherdata card.

> >I think those cards are obsolete because modern Maxen have more than
> >enough of them built in to handle the largest possible number of physical
> >ports you could install.
> 
> No, that's not true - as I suggest above.

BTW, is there a way to show

a) the installed # of HDLC processors
b) the # of them which are currently in use (or still free ;)

A more explanative error message would be nice as well (sth. like "Out of
HDLC processors" in the Message Log).

-- 

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