- A virtual community of network engineers
 Home  BookStore  StudyNotes  Links  Archives  StudyRooms  HelpWanted  Discounts  Login
Re: RE: Interesting DDR Scenario posted 02/23/2002
[Chronological Index] [Thread Index] [Top] [Date Prev][Date Next] [Thread Prev][Thread Next]

>From what I've read it doesn't look like that command would 
help us here.  It's my understanding that command sets the 
priority on the physical interface.  When a dialer interface 
needs to make a call it will choose the interface from the pool 
that has the highest priority.

In our case, we only have one physical interface but two 
logical interfaces.  Would dialer priority work here?


Get your own "800" number
Voicemail, fax, email, and a lot more

---- On Fri, 22 Feb 2002, Bauer, Rick (BAUERR@xxxxxxxxxxx) 

> How about "dialer priority 0-255".
> -----Original Message-----
> From: Wade Edwards [mailto:wade.edwards@xxxxxxxxxxxxxxxxxxx]
> Sent: Friday, February 22, 2002 6:19 PM
> To: John Neiberger
> Cc: ccielab@xxxxxxxxxxxxxx
> Subject: RE: Interesting DDR Scenario
> You would need to set the fast-idle on the lower priority 
> interface to something low like 1 second.  That way when 
there is
> contention for the line the lower priority dialer will get 
> 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 
> 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@xxxxxxxxxx] 
> Sent:	Friday, February 22, 2002 4:44 PM
> To:	ccielab@xxxxxxxxxxxxxx
> 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 
> call, I want Dialer1 to preempt Dialer0 and take over the 
> 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 
> 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 
> 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 
> links to A go away (Dialer Watch).  Now for the twist....  
> 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 
> point-to-point links went down?
> I haven't completely figured out how to do this yet, but 
> a start.  You might configure two Dialer profiles, one for 
> 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 
> 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.  
> difficulty is that the Dialer interface that calls Site B 
> have to have absolute priority.  If the primary link goes 
> because Dialer0 is configured as a backup it might grab the 
> first.  Even if it does get there first, when Dialer Watch 
> kicks in, we'd have to have a way to clear the line 
> 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
> ________________________________________________
> Get your own "800" number
> Voicemail, fax, email, and a lot more
> Commercial lab list:
> Please discuss commercial lab solutions on this list.
> Commercial lab list:
> Please discuss commercial lab solutions on this list.
Commercial lab list:
Please discuss commercial lab solutions on this list.
To unsubscribe from the CCIELAB list, send a message to
majordomo@xxxxxxxxxxxxxx with the body containing:
unsubscribe ccielab