Ken - sorry for late reply. I was on vacation when this was originally posted.
At my last job - I believe what they had is what you mentioned - with Network traffic & phones over same internal network wires. One thing to Note. I think they have 8 "live lines" - in relation to the 12 you mentioned. A particular problem would occur - which is kinda strange - and one you should be aware of. A big selling point on this phone system (ah - installed by the Father of my manager - as the co. his father worked for was in this business - although I don't think the father was personally involved in the Install) - was that the system had its own Conference call ability. You could have a conference call with a bunch of clients - that basically call in to the office - and are all on the call. However, on 1 or 2 occasions (the new phone system was only active for the last 2 mo's I was there) - a single Conf call chewed up 6 of the 8 lines. The deal is - for instance the one time - there were like 3 people all calling in from one office - and then 2 more people calling in from Another office from this particular client. Big mistake - since then many of us needing to call out to clients could NOT - since all the lines were used up. The work around - if multiple people from a client office are calling in - they should Not - and instead - they should all be on a Single line w/speaker p hone in Their office - calling into your office. Anyway - just thought I would throw that out there... -K- -----Original Message----- From: ProfoxTech [mailto:[email protected]] On Behalf Of Ken Dibble Sent: Tuesday, July 07, 2015 4:00 PM To: [email protected] Subject: [NF] Internal Network Considerations for a VoIP Phone System H folks, We are going to replace our existing digital PBX phone system (which has its own CAT3 wiring). I am desperately seeking objective information on the issues from people who aren't trying to sell me something. If any of you have expertise on this topic, perhaps you could answer some questions. My knowledge of telephony is virtually nonexistent, and my knowledge of networking is limited. The current PBX system manages about 150 extensions. We would like to go to at least 200 initially, and perhaps as many as 300-350 later. Existing phone and internet service are both currently provided by Level 3 (formerly TWTelecom). We have fiber coming into the building that carries both phone and internet service. Somehow, using Adtran and PRI devices, the bandwidth ascribed to phone vs internet is dynamically managed in response to demand. However, the internet connection is maximum 25 Mbps down and 5 Mbps up. The system delivers 12 phone "lines". We also have a fax server with a Brooktrout fax card that handles 20 incoming DID numbers and two outgoing (I think "analog") lines, and it has its own Adtran device. The computer data network has 4 48-port gigabit switches. They are NOT POE. Phone vendors want to sell us a VoIP internal phone system using POE switches and our current network CAT5 cabling. My biggest concern is network throughput and avoiding internal network congestion. The phone sales people have trouble understanding this concern. They don't seem to be able to distinguish between congestion resulting from use of the INTERnet as opposed to INTRAnet. My network doesn't suffer from network printing, but it is pretty busy. I am trying to get a straight answer on exactly how much of my internal network bandwidth a very busy VoIP phone system (at times all 12 "lines" are in use) will suck up. There are all kinds of advantages to a VoIP system, I know, but if it slows down the data traffic on the network I am going to be an unhappy camper. I understand that for VoIP to be usable, its packets have to get priority over other data traveling across the network (otherwise the voices "break up"). This is what concerns me about the technology. If there are 12 (or more; growth is inevitable) VoIP conversations taking place at once across my network, what's going to happen to the responsiveness of the constant file server access, accounting database access, and internet access (for the fat-client payroll system and Medicaid billing system) that is also going on across the network? Are there options to add more bandwidth to the network? Affordable options? For example, are there faster-than-gigabit switches that can use the existing CAT5 (not 6) cabling? And would it matter, since the computers only have gigabit network chips? Secondarily, if we dispense with the Level 3 Adtran/PRI stuff and go to SIP networks, am I going to need a lot more INTERnet bandwidth to make that a reasonable option? Any help on this--again, from objective sources not trying to sell me anything--would be very much appreciated. Thanks in advance. Ken Dibble www.stic-cil.org [excessive quoting removed by server] _______________________________________________ Post Messages to: [email protected] Subscription Maintenance: http://mail.leafe.com/mailman/listinfo/profox OT-free version of this list: http://mail.leafe.com/mailman/listinfo/profoxtech Searchable Archive: http://leafe.com/archives/search/profox This message: http://leafe.com/archives/byMID/profox/80838f1ca795b14ea1af48659f35166f1cd...@drexch02.corp.globetax.com ** All postings, unless explicitly stated otherwise, are the opinions of the author, and do not constitute legal or medical advice. This statement is added to the messages for those lawyers who are too stupid to see the obvious.
