Jeez, aren't we being a player hater today... All the other VOIP manufacturers do have something to learn from cisco. from an underlying standpoint, they all can't touch Cisco's VoIP implementation. I have problems from AVAYA from an IP standpoint all the time. They don't have the data features needed to make rolling out IP phones easy. Infrastruture wise, CISCO kills them all. Telephony feature wise, its the other way around. Stability is improving big time. I have several callmanager installs out there that are running great, and the only time we hear issues is when someone screws with something. As for the security issues, what kind of idiot doesn't firewall the servers?? Shut off all unneeded traffic to the voice server vlan. Even restrict certain IP's to only be able to talk to it.. On the newer AVAYA solutions, their CLAN and MEDPRO boards aren't able to be attacked (yet) their servers sure are though. Since their servers run linux, exploits are coming out more and more everyday for these. The servers have httpd, ftpd, telnetd, sshd, and a few others open to the world. But once again, FIREWALL it.
As for voip implementations, Cisco and AVAYA are 1st and all the others are far behind in my opinion. Now depending on what you want/need to do decides who's actually #1. Its cheaper overall to have a Cisco Callmanager system. You have that data gear for your data network, so that'll be covered under SmartNet, then any other voice gear you throw into those boxes will be covered under that same contract. Now AVAYA on the other standpoint, they charge maintenance per port on your system. Its very expensive and this is the #1 reason why people don't chose AVAYA over cisco for example, or let alone look for other solutions in the 1st place even if its not VoIP..
Also comes into play is traditional PBX vendors closed sourced thinking. Cisco can have apps written for it, although most of them are worthless, but its still open. AVAYA, you have to pay just to get information from them. They don't like to give information out. I called up for support on T.38 Fax relay on their system and they wanted to charge me 750 bucks to get that info. Cisco, its
and look.
There are plus and minuses to each system. You need to look at the actual things that you need from the PBX. Call center, go with traditional no question. Campus style setup with tons of remote sites with 20 stations, CallManager all the way, price point can't be beaten on setups like this.