What are the best messaging and VOIP systems for medium to large corporate networks?
What have you found to be the best in your experience and why?

It should support:

  • Instant messaging
  • Video and audio calls
  • File transfer
  • And it should be easy to setup - 10 servers with arcane configs, not accepted

Bonus features would be:

  • Conference calls (multiple participants)
  • Screen sharing

I expect a server/client setup, though a client-only solution (P2P) would be welcome as well.
If the system is open-source, then its perfect for my setup.

I've heard of:

5 Answers 5


Microsoft Office Communication Server 2007 R2 is an excellent product. It has all the features you've mentioned and more should you need them (like integrating with hardware PBX's and what not).

In my organisation we have 300 employees across 2 geographically distant sites so we had a Standard Edition OCS server at each site. The only downside is there is no easy way to manage contact lists for users you have to use the Resource Kit's LCSAddContacts.wsf script.

We started out using a Jabber Server which was free called OpenFire I think. It was simple and has LDAP integration but we favoured OCS in the end because of centralised administration of user accounts, it's video/voip functionality and the fact the client integrates seamlessly with Outlook and Sharepoint.

If you need more info just let me know.

  • I would hope that scripting is coming for the next release of OCS
    – Jim B
    Sep 1, 2010 at 2:01
  • As users don't need to add or approve eachother to start talking (just use the builtin search in the client) I don't see the scripting of user's contacts as a problem. If they want to add contacts to quickly spot presence they can do it manually, I can still chat with them regardless, one-click from their mail in Outlook or whatnot ^^ Sep 1, 2010 at 9:13
  • Thanks for the info, I'll look into it and let you know if I need help! Sep 1, 2010 at 9:42
  • The contact list/script thing was only a problem for us because we wanted to keep the user experience as similar as possible to the Jabber/Pidgin setup we had which has contacts lists organised by team. Oskar is completely correct though all users can find and communicate with each other without the need for the script. Sep 1, 2010 at 20:25

You could always look at open-source solutions like freeswitch and asterisk... Pair either of those with a XMPP server like Openfire and their native Spark client or any flavor of XMPP client of your choosing, and you can do everything you're talking about very seamlessly. There are a few pre-built distributed images you can use for $0.00. Elastix might be just what you're looking for.


I've used OCS and I've used Sametime. OCS just plain works. It's not a simple set up but you can get it going without too much trouble (it just alot of little things), and maintenance is relatively straightforward. Sametime seems to need a herd of babysitters to keep it running everywhere I've used it, and of course it's not something you can just pick up because its pretty quirky in the way it works (although Notes admins seem to understand it- which should give you an idea of why it's not an install and run product).

I'd probably look at OCS, Bigant (open source et al) then finally, if I was forced to I'd evaluate Sametime.


Only one I've used is OCS. I've not been involved in the back-end config, so not sure how many servers are really required... if your environment is already a Microsoft Office/Exchange/Sharepoint, it may not be so hard as starting from scratch.

The Microsoft Office Communicator client is intuitive, and ties in with the other Microsoft products really well. You may consider that a pro or a con.

It's expensive, but very easy for users to pick up. No experience with any similar Open Source products, so I can't really offer suggestions there.

Could Skype work? Also very easy to use (managed to train my parents), quick to install (client side only needed). It offers IM, voice, video; but I realise it doesn't meet all of your requirements.

Finally, are you sure your network is ready for this? If you are all on one high-speed switched campus, you should be fine, but if you need to run over slower speed WAN links, you'll need to ensure that there is sufficient bandwidth - lots of point-to-point video streams will start hammering your network and affect other applications.

  • It doesn't need a lot of servers, a single Standard Edition server can support up to 5000 users. In terms of licensing it can get complicated because there are different levels of CALs and client licensing options. In a corporate environment I'd never recommend using products like Skype, there are often clauses that mean any conversations over those products belong to the company (MSN Messenger used to have that clause and still might) plus you're trusting all your conversations to these other companies, not good if you are discussing private business Sep 1, 2010 at 20:29

If you are looking for one big tool doing everything I think MS Office Communicator is a good choice.

For instant messaging, we use dMessage as a dedicated tool for IT support because you can send pop-ups to users according to their workstation configuration (presence of a specific file or application on the workstation, server ...).

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