Asterisk features for Business use

Hi All,

I have some questions concerning the capability of Asterisk. We currently run a 3Com NBX system and have some fairly complex setups with bridged extensions.

Is Asterisk capable of supporting a phone with a button configured which represents another extension? When that extension is in use, the light will be ‘lit’ and when that extension rings, the light will flash and also (optionally) ring on the configured phone - i.e. ring on both phones at the same time?

The scenerio where this is used is where someone has a personal assistant and the PA can answer their call if/when required.

Also, I gather no-body has got 3Com phones to work with Asterisk - given they start looking for an NCP on layer 2 straight away? I would think this is a pretty big ask… Has anyone ditched NBX for Asterisk? If so, what was the main reason? Mine a building up from constant problems and just overall functionallity that isnt there or is always promised but never delivered or is delivered half arsed - SIP being one of them.



I have not ‘ditched’ 3Com… I am a 3Com Tech, and their system is great, as long as it offers the features that you need. Although I will not put one in my office. I use asterisk. For me being a small company, asterisk saves me a ton of money in licensing and hardware. And gives me more flexibility.

I have been learning asterisk over the last few months, and have to say that asterisk is incredibly powerful, and will be a major player in all VOIP solutions that I install/sell/recommend.
Both systems have their strengths and weaknesses.
Just about everything that you do in the NBX can be done in asterisk. If you have phones that will support it.

3com phones do not use sip, and run at layer2 by default. You have to enable IPonTheFly in the NBX to make layer3 available, but they will only request an IP if communicating with a device on another subnet. But then that is a whole other can of worms (GRE, Broadcast, More 3Com hardware for the tunnel) and I have never been happy with it.

What NBX and software are you running?

My thoughts on the 2, keep in mind I am relatively new to asterisk.
Auto Attendants, are easier to record and listen to in the 3com. But more powerful in asterisk.
Call groups, about the same.
Advanced call routing (dial plan), about the same. Maybe easier in asterisk.
Asterisk has more hardware choices, but 3Com builds thier own hardware so it generally works out of the box.
3com has a full featured web interface. I use freePBX, it is great but not as powerfull as 3Coms. Yet.

These are just some of my observations, take them with a grain of salt.


We use 1 x V5000 and 2 x V3000’s - all running R5 (this week it is 0.22). We have had a number of firmware changes recently to try and resolve issues such as dropped calls, one way audio and conferencing issues. All of which are fairly fundamental to a business phone system.

The user interface to the system is rather important and one of the things I meant to ask about - I gather that the web interface to Asterisk is via another package? People here are very used to self serving diverts etc.

The other aspect that 3Com (and probably every other proprietry system) has is the centralised configuration of phones. For what I have worked out, you plug in your VoIP hardphone, and you then have to configure it for your server etc etc. Some phones support DHCP configuration to an extent but there is almost always a need to get into the phones on web interface to do something.

The 3com phones you plug in, and they work everything out for themselves. You just get into the NBX web interface (central) and configure it from there - assuming the default setup isnt what you want.

I guess my aim here is to get an idea if it is feasable for us to drop all our 3com gear for Asterisk. Probably my main concern is the support that is available - but then again (and no offence here) I have never been overly confident of 3Com’s support capability.

Asterisk does have supported versions “Asterisk Business Edition”, and “Enterprise Asterisk”.

None taken. I am not a 3Com employee. I have worked with 3Com a lot with support issues, and have had mixed results. I find that the best help I have had has been when working directly with the engineers that designed the system.

I cannot personally attest to the support from Digium, as I am an open source (read in it for the free stuff) guy on this project for now.
Asterisk Business Edition may have a web GUI interface, I cannot say.

The package I use is freePBX. And because I am testing in a small office i use trixbox. Trixbox is an all in one distro based on CentOS. It includes Asterisk, freePBX, SugarCRM, and a few other really nice additions. Probably not up to snuff for large systems, but a great way to get your feet wet.

There are phones compatible with asterisk that support auto provisioning via tftp. How closely this matches the NBX, i have not tested.

All in all, asterisk is a great system. I have had more little issues, ie. voicemail sound, analog line card setup, ata setup, etc. as would be expected from an opensource system. The nice thing (and bad thing) about propritary systems, like the 3Com is that they make the hardware and software, which usually means that it will work well together, and in 3Com’s case auto detected and setup for you.

I would imagine that you have a lot of money tied up in 3Com hardware right now, and I am not going to be the guy to convince you to walk away from that into an Asterisk system. But, with an PC and some time, asterisk could be tested in your office with a minimal outlay of cash.
Get an older PC, install trixbox, and get a few Cisco, Snom, Aastra, or Polycom SIP capable phones and try for your self.
An analog card, 2 phones, a PC and Trixbox could be setup for under $700.00. (TDM02B 2 port FXO card $250.00, 2 Polycom Soundpoint IP 430 POE phone $150.00 each, spare pc in office free, trixbox/asterisk free)

If you are really having that many issues, it may be somethig to investigate.

Just out of curiosity…
I assume 3 Locations, 1 Corp. 2 satellite (with the v3000’s). Correct?
How are the locations connected? Leased lines or VTL’s? If you are using leased lines, how big, what compression on the phones, QoS?
Are you having issues on the same subnet? Dropped calls, one way audio, conferencing, or across the subnets?
What phones? 3101’s 3102’s etc…
I am sure you have gone through all of this with your 3Com rep, it is really just for my own curoisity.

Another great place to get more info on asterisk is

Maybe we can get some asterisk verterans to chime in here…

Thanks for your comments - all good information.

I think I will do just that - run it up and see what it can do.

We actually have 5 sites in total with the three NBXs hosted at the main sites. The two smaller sites run over a 2Mb serial or ethernet connection back to the main sites - i.e. different subnets. The main site (HO) runs the V5000. We have a mix of mainly 2102 and also 3102’s. We run VTLs between all three systems to cut the old phone bill. The links between the big offices are all Ethernet - at least 4Mb with redundant connection of 1 or 2Mb. I can ping a device on the subnet furthest away from me physically and get an RTT of 42ms.

Our PC network is all based on Citrix with Wyse thin clients - so the WAN links are very lucky to break any kind of sweat - its more so the printing that causes the spikes.

The dropped calls and one way audio happens between sites/subnet. The conferencing issue is at a site with two paths into it - with the secondary link down it works - otherwise it either doesnt work or you get a one way audio. I was out there last week to get a trace.

I am not running any kind of QoS mainly because the links are not utilised heavily. I am however, reconsidering my options. All our routers are Cisco. As far as what the compression is on the phone, I am not sure.

If you have any pearls of wisdom, do pass them on!



How many phones and thin clients going across those 2MB links?
Are the dropped calls random? Or easy to diplicate?
It almost sounds like a QoS or bandwidth issue. An easy test would be to turn on QoS in the routers if they support it, otherwise, in NetSet, set the audio compression for the remote phones to g729 from g711. That will save a lot on bandwidth needed for each call.
Codec BR NEB
G.711 64 Kbps 87.2 Kbps
G.729 8 Kbps 31.2 Kbps
G.723.1 6.4 Kbps 21.9 Kbps
G.723.1 5.3 Kbps 20.8 Kbps
G.726 32 Kbps 55.2 Kbps
G.726 24 Kbps 47.2 Kbps
G.728 16 Kbps 31.5 Kbps
BR = Bit rate
NEB = Nominal Ethernet Bandwidth (one direction)

Just a thought, not knowing your setup makes it difficult to diagnose.

agreed, IMHO QoS should be your first step. I ALWAYS set up QoS on WAN links and VPN’s, wether its needed or not.

engjohn, maybe you can answer a quick question. I’ve got quite a few 3com NBX phones laying around. I can’t seem to find any definitive proof that these phones will work with Asterisk. Some people say that since they are H.323, it shouldn’t be a problem. But I haven’t found anyone that has actually had them work. Do you know if they will?

I too am wondering if anyone has gotten an NBX to communicate with an Asterisk server

From what I have read the 3Com phones won’t work directly with Asterisk since they download their flash from the NBX. However theoretically one could use 3Com’s H.323 Connexions software to create a H.323 between a NBX and Asterisk server?

Anyone ever get this working?