Having worked building a Carrier's ATM-F/R backbone, I can tell you that the scenario you posted isn't as unique as it may seem.
First of all, as you stated correctly, DLCIs are locally significant on a per INTERFACE basis. That concept applies to both, the WAN switch and the CPE. Carrier's WAN Switches typically have plenty of INTERFACES (physical ports) to provision customer PVCs on. Therefore, Carriers can provision as many DLCI=16 for instance, as F/R interfaces each WAN Switch has. At the hub location, the Carrier most likely will assign you a brand new Interface (physical port). Therefore, you the customer, have the entire range of DLCIs to request from the Carrier (16 through 1007 on Cisco WAN switches). There are WAN Switch Module DLCI limitations, depending on what type and brand of WAN switch Carries use. At each of the spoke locations, depending on the CIR your particular PVCs require, the Carrier will either provision your PVC on an existing but under-utilized Interface (meaning that you may or not get the DLCI you want, although most likely you'll get what you ask for). Or if your PVC's CIR is "fat" enough, it will be provisioned on a brand new Interface. Therefore, you'll get any DLCI you want or ask for, provided that the Carrier's DCLI policy allows it, and most do I believe. Now, mapping customer's F/R PVC DLCIs to ATM PVI/VCIs is a whole lot different beast on its own. But, that doen't have anything to do with assigning similar DLCIs at the spoke sites. Hth, Thanks, Angel -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]On Behalf Of Kelly Cobean Sent: Thursday, June 27, 2002 7:08 AM To: [EMAIL PROTECTED] Subject: RE: frame relay question [7:47498] You know, this brings up a good question...My company has sites all across the country, and for every spoke site, we were able to get the exact same DLCI, and at the hubs, we were able to get a range of DLCI's in increments of 5 going out to each of the spokes. How is this possible? I completely understand that the DLCI is locally significant, and that it only defines the connection between the Frame switch and the customer CPE, but what are the odds of the exact same DLCI on so many different switches being available? Maybe there is something relevant to the fact that the carrier's network is actually using ATM that makes this possible? Thanks! -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]On Behalf Of Chuck Sent: Wednesday, June 26, 2002 3:09 PM To: [EMAIL PROTECTED] Subject: Re: frame relay question [7:47498] good questions. in theory, you may request any dlci you wish, so long as it is in the legal range for the carrier. this would be numbers 16 through 996? for some, or through 1004? for others in fact, if you have a good rapport with your carrier, and they in turn have their act together, this is common practice. OTOH, in my experience, telcos just want to get the work done, and they will configure the dlci starting with 16 because it's easy to remember. the switch techs just bang out their configs with no conscious thought intervention. if you have nothing fancy going on ( and it appears you don't ) the only required configuration on your router is setting the frame relay encapsulation, and setting the ip address. at that point the circuit will come up. you can check this using the show frame pvc, show frame lmi and show ip interface brief commands. lmi will detect and use the single pvc with no other tweaks required. if you have multiple pvcs on a circuit, you would, of course have to use frame map commands, or use point-to-point subinterfaces in conjunction with the frame interface-dlci command. best wishes. ""GEORGE"" wrote in message [EMAIL PROTECTED]">news:[EMAIL PROTECTED]... > I have a newbie question, regarding frame-relay. When I order a frame > relay circuit for two locations > Do the telco provide the dlci? Or I make it up? Once the frame relay is > installed on both locations I guess using the dlci numbers it makes the > connection , besides the ip and all other stuff > Can someone explain it please > thanks Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=47563&t=47498 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
