From: John Neiberger (neiby@xxxxxxxxxx)
Date: Fri Feb 22 2002 - 20:41:45 GMT-3
   
That's a great idea.  I was thinking along the lines of
priority, but dialer priority doesn't do what we're trying to
accomplish.  I think your idea would work well.
Thanks again,
John
---- On Fri, 22 Feb 2002, Wade Edwards
(wade.edwards@powerupnetworks.com) wrote:
> You would need to set the fast-idle on the lower priority
dialer
> interface to something low like 1 second.  That way when
there is
> contention for the line the lower priority dialer will get
disconnected
> after 1 second of inactivity and the higher priority line
will be able
> to call.
>
> You might want to set the fast-idle on the higher priority
dialer
> interface to something high so it will not be easily
preempted by the
> lower priority dialer interface.
>
> L8r.
>
>  -----Original Message-----
> From:         John Neiberger [mailto:neiby@ureach.com]
> Sent: Friday, February 22, 2002 4:44 PM
> To:   ccielab@groupstudy.com
> Subject:      Interesting DDR Scenario
>
> I posted this on the regular list but since I haven't figured
> out the solution yet I thought I'd post it here, as well.  To
> summarize what you're about to read, I need to figure out how
> to give one Dialer interface priority over another when
> accessing the same BRI.  So, if Dialer0 (low priority) has
> placed a call, if Dialer1 (high priority) then needs to place
a
> call, I want Dialer1 to preempt Dialer0 and take over the
BRI.
> Here's the full post:
>
> <snip>
>
> I was just talking to a guy I work with about this and I
> thought it was an interesting scenario.  It was his idea and
my
> first thought was that it wasn't possible, but then after a
> little more pondering I decided that it might be possible.
> Note:  'possible' does not mean desirable.  :-)    Here's the
> scoop:
>
>
>
> [A]-----------------[B]
>   |  \
>   |    \
>   |      \
>   |        \
>   |          \
>   |            \
>   |              \
> [C] ----------- [D]
>
> Site A is connected to B, a disaster recovery facility, via
> frame relay.  A also has point-to-point connections to sites
C
> and D.   C and D are connected via frame relay but obviously
> only use the frame relay link to reach A if their own primary
> link goes down.
>
> C and D have ISDN connections configured to dial B in case
both
> links to A go away (Dialer Watch).  Now for the twist....
What
> if you wanted to configure C to dial D when the load on its
> primary link reached a certain point, yet still dial B if
both
> point-to-point links went down?
>
> I haven't completely figured out how to do this yet, but
here's
> a start.  You might configure two Dialer profiles, one for
each
> destination.  On the major interface on C you'd configure
> Dialer0 as your backup interface and configure an appropriate
> load.  When the line utilization reaches that load, the
router
> would dial Site D.
>
> Then you might configure Dialer Watch on Dialer1 and make it
> dialer Site B if routes originating from Site A disappear.
The
> difficulty is that the Dialer interface that calls Site B
would
> have to have absolute priority.  If the primary link goes
down,
> because Dialer0 is configured as a backup it might grab the
BRI
> first.  Even if it does get there first, when Dialer Watch
> kicks in, we'd have to have a way to clear the line
immediately
> so Dialer1 could dial out.
>
> Is that possible?  Admittedly, I'm a bit weak on DDR of this
> variety, but this sounded like an interesting brain teaser.
>
> Regards,
> John
>
This archive was generated by hypermail 2.1.4 : Thu Jun 20 2002 - 13:46:31 GMT-3