A benefit to DSL as backup is that you should immediately known when it goes down. This allows you to have the telco begin repairs while your primary circuit is functioning. With ISDN, if you don't use it very often there may be a problem with the line and/or equipment and you'd have no idea until the primary failed. As far as I'm concerned, I'd rather not wait until my primary fails before I discover that my backup also is not functioning. This has happened a couple of times in the last year with ISDN and it's a little frustrating.
So far, I haven't had an instance where a primary frame relay circuit was down at the same time as a DSL backup circuit except for when Backhoe Bob has attacked one of our locations and dug up the lines. In that case, ISDN would have failed as well so it's no big deal. John >>> "Priscilla Oppenheimer" 12/4/02 2:49:11 PM >>> It sounds like DSL has a low mean time between failure (MTBF) but a high mean time to repair (MTTR), which can be just as bad, especially if it's your only backup. Of course, your mileage may vary (YMMV), depending on the service provider. Also, a service level agreement (SLA) would help, as Chuck mentions. Does that message set a record for the number of acronyms used? :-) Priscilla The Long and Winding Road wrote: > > ""Mirza, Timur"" wrote in > message > [EMAIL PROTECTED]">news:[EMAIL PROTECTED]... > > we are looking to migrate isdn backup at our retail stores to > dsl...is > there > > anyone that has performed this already? > > > CL: having done a number of data networks that were DSL based ( > but none > migrating ISDN to DSL ) I can offer this consideration: if a > DSL link goes > down for whatever reason, it may take more than a couple of > days for your > telco to get it back up and working. You will want to have some > solid > service level agreements in place. DSL on the whole is > extremely reliable. > The problem tends to be during those rare instances when it is > down for > whatever reason, some telcos seem to have DSL repair low on > their priority > list. > > CL: other than that caviat, why not? > > > > > > Timur Mirza > > Principal Network Engineer > > Network Planning & Engineering, West Region > > 15505-B Sand Canyon Avenue > > Irvine, California 92618 > > Verizon Wireless > > 949.286.6623 (o) > > 949.697.7964 (c) Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=58576&t=58568 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
