Hemingway wrote: > > b.) the DLCI is not a globally unique identifier, like the > MAC address in > > the case of an Ethernet switch, rather has only local > significance and it > > might change along the path (aka PVC) from switch to switch. > > > Actually, there is such a thing as a "universal" DLCI. PVO and > I and a > couple of other folks researched this thoroughly one Saturday a > couple of > years ago. It is an extension to the standard, and allows( > going from memory > here ) for an extended DLCI field that supports a 15 bit > identifier. This > means that a unique DLCI is assigned to every customer device > in the cloud. > > To my knowledge, no telco supports this, for a lot of reasons, > not the least
There's got to be some use for that Extended Address (EA) bit! :-) It can actually be in the header 4 times. If it's set to 0, it means the next byte has more DLCI address bits in it. A DLCI can be 10 bits, 16 bits, or 23 bits. The fields that most of us know hold the 10-bit DLCI look like this: 6 bits DLCI, C/R bit, EA=0 4 bits DLCI, FECN, BECN, DE, EA=1 But here's another standard option: 6 bits DLCI, C/R bit, EA=0 4 bits DLCI, FECN, BECN, DE, EA=0 6 bits DLCI, 0, EA=1 And yet another standard option: 6 bits DLCI, C/R bit, EA=0 4 bits DLCI, FECN, BECN, DE, EA =0 7 bits DLCI, EA=0 6 bits DLCI, 0, EA =1 Priscilla, yet another purveyor of protocol trivia :-) > of which is the complexity and the lack of capacity to support > end to end > across several provider networks. > > An enterprise running it's own frame network, say using > Stratacom equipment, > for example, might find this of value. > > I've done a couple of quick looks on CCO and have not found any > links. My > recollection is that we researched outside of cisco to find the > info, and > there may be some links on CCO but my phrasing is not turning > them up > > just another bit of pretty much useless information I've run > across over the > years. :-> > > Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=71382&t=71263 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
