+ Post New Thread
Results 1 to 11 of 11
Wireless Networks Thread, To VOIP or not to VOIP, that is the question in Technical; Hello everyone, first time poster here... I am the ICT Manager/Technician at a school in Somerset where we are looking ...
  1. #1

    localzuk's Avatar
    Join Date
    Dec 2006
    Location
    Minehead
    Posts
    17,089
    Thank Post
    511
    Thanked 2,308 Times in 1,784 Posts
    Blog Entries
    24
    Rep Power
    803

    To VOIP or not to VOIP, that is the question

    Hello everyone, first time poster here...

    I am the ICT Manager/Technician at a school in Somerset where we are looking at replacing our existing phone system. We currently have a digital PBX and standard digital phones but we have outgrown its capabilities.

    So, we have a few options: get another similar system installed with the extra functionality at considerable cost or do it in house using off the shelf or open source VOIP equipment for a much lower cost but increased work for myself (which, I must admit won't be a major problem).

    Has anyone had any experience of implementing a VOIP system in their school? Am I taking too much on thinking of doing this?

    Some details of what we have and what we want:

    Have: 20 extensions - nothing fancy, call transfer, conferencing etc... 3 analogue PSTN lines in the system and 1 for a fax line

    Want: 30 - 50 extensions, some wireless/dect - with 2 way radio functionality to remove the need for a seperate radio system, voice mail for each member of staff (with option of sending it to email inbox), phone to phone messaging (ie similar to SMS) to reduce the need for 'runners' with messages from the office, a on computer interface for the receptionist (dragging and dropping of calls, sending of messages etc...). Plus the standard stuff such as conference calls.

    I have already set up an Asterisk server and a couple of software SIP clients to test it out and see how difficult it would be to setup/manage and I am liking it. I am in the process of buying a couple of cheap hardward SIP phones to try out also.

    One of the key areas that we have to consider, as far as I can see, is QoS on our switches (which are all too old to support it but are due for replacment next year anyway). Has anyone got any ideas about this side of things?

    I look forward to your responses!

  2. #2


    Join Date
    Jan 2006
    Posts
    8,202
    Thank Post
    442
    Thanked 1,032 Times in 812 Posts
    Rep Power
    338

    Re: To VOIP or not to VOIP, that is the question

    One of the key areas that we have to consider, as far as I can see, is QoS on our switches (which are all too old to support it but are due for replacment next year anyway). Has anyone got any ideas about this side of things?
    You should get this side sorted first, some decent managed (layer3) switches and use vlans. You don't want the phone system out of action if there is a network error/virus/DoS. Better to segregate the phone system entirely rather than rely on QoS.

  3. #3

    localzuk's Avatar
    Join Date
    Dec 2006
    Location
    Minehead
    Posts
    17,089
    Thank Post
    511
    Thanked 2,308 Times in 1,784 Posts
    Blog Entries
    24
    Rep Power
    803

    Re: To VOIP or not to VOIP, that is the question

    Hmm... I shall have to go back to my uni notes and read up on vlans a little more. I understand their usage to prevent broadcast storms by segregation, but how does it apply to this sort of set up? Can you dedicate bandwidth by vlan?

    Also, we currently use Dlink network gear, and I am keen on moving to HP stuff. What do other people use?

  4. #4

    plexer's Avatar
    Join Date
    Dec 2005
    Location
    Norfolk
    Posts
    12,964
    Thank Post
    586
    Thanked 1,494 Times in 1,340 Posts
    Rep Power
    397

    Re: To VOIP or not to VOIP, that is the question

    well a vlan is just that a virtual lan so you can use one to confine all of your voip to their own virtual lan which means you won't have a qos problem when voip traffic would otherwise be fighting with data traffic to arrive in the correct order.

    Ben

  5. #5


    Join Date
    Jan 2006
    Posts
    8,202
    Thank Post
    442
    Thanked 1,032 Times in 812 Posts
    Rep Power
    338

    Re: To VOIP or not to VOIP, that is the question

    I understand their usage to prevent broadcast storms by segregation, but how does it apply to this sort of set up?
    If the network is segregated to smaller broadcast domains the effect is to increase bandwidth for that vlan, the voip network is 'protected' as it is isolated from the computer network on the other vlan. I suppose you are dedicating bandwidth because (when not using frame tagging) each vlan has its own uplink - my understanding is that if vlan 1 becomes saturated, vlan2 isn't affected - hopefully someone can clarify this.

  6. #6

    Ric_'s Avatar
    Join Date
    Jun 2005
    Location
    London
    Posts
    7,582
    Thank Post
    107
    Thanked 761 Times in 592 Posts
    Rep Power
    179

    Re: To VOIP or not to VOIP, that is the question

    @localzuk: What is your existing phone system? We currently have an Avaya IPOffice (a digital system, despite the name) but since the upgrade to IPOffice v3, it now supports IP handsets too.

    As we add additional extensions in the future, I intend to use IP phones instead of digital ones. admittedly th phones are more expensive but the cabling costs are reduced since existing (or easily added) Cat-5e can be used.

    You seem to have a good idea of what you are ultimately after so I think it is more of a process of finding prospective systems. I would also make sure you have a comprehensive maintenance cover on the system. Telephones are your school's link with the outside world and you cannot afford to be without a phone system for more than an hour or two at the most.

    From experience, I would also recommend you review the number of lines that you have. If you increase from 20 to 40 (for examlple) extensions, the demand for concurrent calls is bound to increase. We have 3 ISDN lines (i.e. 6 lines) and that regularly fills up with 20-30 extensions.

  7. #7
    ChrisH's Avatar
    Join Date
    Jun 2005
    Location
    East Lancs
    Posts
    4,938
    Thank Post
    114
    Thanked 272 Times in 250 Posts
    Rep Power
    104

    Re: To VOIP or not to VOIP, that is the question

    Quote Originally Posted by Ric_
    We have 3 ISDN lines (i.e. 6 lines) and that regularly fills up with 20-30 extensions.
    .... and one of those lines is guaranteed to be busy if Ric is in work

  8. #8

    john's Avatar
    Join Date
    Sep 2005
    Location
    London
    Posts
    10,439
    Thank Post
    1,468
    Thanked 1,035 Times in 908 Posts
    Rep Power
    299

    Re: To VOIP or not to VOIP, that is the question

    Have you guys never head of Skype or MSN, think of the cost to the school! and if your lines are getting full don't forget ISDN30 may be the next step up.

    As for phone systems, I saw a nice Cisco one the other day, looked very shiney! but having room to upgrade is what you need

  9. #9

    Ric_'s Avatar
    Join Date
    Jun 2005
    Location
    London
    Posts
    7,582
    Thank Post
    107
    Thanked 761 Times in 592 Posts
    Rep Power
    179

    Re: To VOIP or not to VOIP, that is the question

    @john: You cannot tell us to use Skype/MSN to chat and then tell us to get a Cisco phone system - the cost of Cisco far outweighs any savings!

    Besides... no Skype or MSN possible here

    Something that would be interesting to look into is the IP routing services of the Avaya system... it can route calls via Internet services for lower call costs. It will also make its own mind up as to which route is cheapest.

  10. #10

    Geoff's Avatar
    Join Date
    Jun 2005
    Location
    Fylde, Lancs, UK.
    Posts
    11,800
    Thank Post
    110
    Thanked 582 Times in 503 Posts
    Blog Entries
    1
    Rep Power
    223

    Re: To VOIP or not to VOIP, that is the question

    If you want to go the open source VOIP route you need to be looking at Asterisk.

    http://www.asterisk.org/

    You should probably start off with a premade liveCD.

    http://www.automated.it/asterisk/
    or
    http://www.trixbox.org/

    and some software IP phones.

    http://www.voip-info.org/wiki/index....nes#SoftPhones

  11. #11
    budgester's Avatar
    Join Date
    Jan 2006
    Location
    Enfield, Middlesex
    Posts
    480
    Thank Post
    4
    Thanked 37 Times in 30 Posts
    Rep Power
    23

    Re: To VOIP or not to VOIP, that is the question

    If you want a supported Linux VOIP platform with hardware etc.

    You could try http://www.splicecom.com/

    We have it installed here, with around 100 extensions, and they have just added SIP trunk support.

    If you really want to get flashy check out the PC400's think electronic registration with these puppys.

SHARE:
+ Post New Thread

Similar Threads

  1. VoIP
    By Oops_my_bad in forum Wireless Networks
    Replies: 4
    Last Post: 15th November 2007, 09:41 PM
  2. VoIP Solution?
    By Samson in forum Wireless Networks
    Replies: 12
    Last Post: 2nd October 2007, 09:08 PM
  3. vlan VoIP question
    By CyberNerd in forum Wireless Networks
    Replies: 4
    Last Post: 14th June 2007, 07:57 PM
  4. VOIP suggestions
    By nawbus in forum Wireless Networks
    Replies: 7
    Last Post: 19th September 2006, 11:29 AM
  5. VOIP over Network
    By shane_southampton in forum Wireless Networks
    Replies: 2
    Last Post: 22nd September 2005, 01:23 PM

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •