> -----Original Message----- > From: John Lange [mailto:[EMAIL PROTECTED] > Sent: July 28, 2006 10:26 AM > To: [email protected] > Subject: RE: [on-asterisk] PoE > > On Fri, 2006-07-28 at 00:55 -0400, Jim Van Meggelen wrote: > > each environment has to be evaluated on its own. > > In some cases re-using the voice wiring makes sense, in > others it will not. > > No disagreement here, there are always special cases and each > situation has to be evaluated on its own merit. > > For the purposes of this discussion I was assuming what I > feel is a fairly typical situation; workstations with both an > existing cat5 drop and a cat3 drop where the cat5 network is > a bit of a mess of routers, switches and hubs. > > Given the above and ignoring special cases and politics; what > are the relative merits of using the cat3 network vs. > upgrading the cat5/LAN network?
It puts all the sets on their very own LAN, which means there is zero chance of them having to contend with any other LAN traffic. Since there is nothing fancy going on with either LAN, there is no need to put in expensive mansged switching equipment, followed by expensive labour to design, deploy, test and support this new LAN. "Keep you old switches and network spagetti, we don't need to (nor want to) touch it, and the hardware for the voice LAN will be about $5 per set". > I was interested in hashing through this discussion because > its probably a situation that many of us encounter frequently. It is. > Personally, I feel the convergence aspects of VoIP are one of > its main selling features. Proprietary private phone systems > with their own networks is exactly what VoIP/Asterisk > purports to avoid. I don't see convergence as having anything to do with how the devices connect to the network. For me, convergence is about making voice an application that is able to integrate with other network applications. For the most part, this still happens at the server level. And, even if the client (i.e. the phone) will eventually integrate with network services, it is easy enough to create a route between the voice and data LANs. > So the concept that setting up a parallel network just for > phones would be better and less expensive goes against what I > would expect. That's why I wanted to hear from the CAT3 side > of the argument to make sure I wasn't missing anything. It greatly simplifies the rules that have to be applied to either network. The data LAN can keep doing what it is doing, where each device gets whatever bandwidth it can grab, and the voice LAN will have plenty of bandwidth for voice, with no chance of some errant network device rendering every phone out of service. > So far, while I understand there are always special cases, I > haven't heard anything that leads me to believe that setting > up a parallel network based on existing CAT3 cabling would be > less expensive. Probably the only way to obtain such data is from empirical evidence. In my experience, using the Cat3 is very consistent in terms of effort and results (and thus cost), whereas messing around with an existing data LAN is seldom simple, and upgrading an existing LAN is fraught with politics and/or a total lack of desire to invest the capital. One of the things you said that struck me was ". . . ignoring special cases and politics . . .", which I found ironic because those two reasons are significant factors in why it can be so much trouble dealing with an existing LAN. I would argue that all cases tend to be special, and politics nearly always plays a part. This matter is one that is going to continue to evolve, and the days of re-using Cat3 are probably nearing their end, but so far it has been my experience that this option is worth examining in all cases; having this option proves useful more often than not. Jim -- Jim Van Meggelen [EMAIL PROTECTED] http://www.oreillynet.com/pub/au/2177 "A child is the ultimate startup, and I have three. This makes me rich." Guy Kawasaki -- -- No virus found in this outgoing message. Checked by AVG Free Edition. Version: 7.1.394 / Virus Database: 268.10.4/402 - Release Date: 27/07/2006
