- Security. While not directly related to the handsets per se, you should always take into account the technology's security. Evaluate the relative security of each vendor's system -- unfortunately experience has shown that they are quick to say their systems are the most secure, but quickly move on to "bag" their competition. In our recent experiences this information about competitor's products is unfounded and misguiding. Being critical network infrastructure, the CSO and his or her security team should be brought in to consult and test on each and every VoIP platform considered -- ensure that no stone is left unturned when testing.
Encryption is offered by most vendors, so make sure it is used. Watch out for overloaded VoIP systems particularly with the overhead of security. Some quote maximum gateway users and bandwidth with the minimum feature set and no security.
Give the feature set and security deemed necessary for your voice information/data transmissions to the vendor and ask for a specific capacity projection for your specific VoIP system. Also get that in writing prior to handing over the contract. Don't forget physical security also, and remember wherever there is a handset there is also an opportunity for a hacker to enter the building, disconnect the phone and jack into the network so it is advisable to run a separate switch or VLAN for your VoIP network.
- Power over Ethernet. PoE is another important consideration when thinking about IP handsets. Many network switch vendors are producing switches that can supply PoE, which injects power over the network cable to power network connected devices, such as IP cameras, IP phones, wireless access points, etc. This removes the need to install new/more power points as well as needing to use the common "brick" power pack transformers that most handsets ship with.
3Com was kind enough to lend us a 3C17205 SuperStack 3 4400PWR 24 port network switch that supplies PoE (this is a 1U device). We found that it powered all VoIP handsets supplied to us for this review (all that supported PoE, that is), including 3Com, Avaya, NEC, and Zultys handsets. At one stage we had 13 handsets running happily from it.
- Protocols. This is one of the rockiest issues currently facing the vendors, and each vendor has its own extended version of the "standard" protocols, usually H.323 or SIP. However, there are some other ones out there that anyone trying to evaluate VoIP systems will come across.
There does appear to be one standard many researchers of VoIP are hearing more often than not these days -- SIP (Session Initiation Protocol). This provides a basis for vendors to create connectors using SIP for their VoIP devices, handsets, gateways, software, and son on. This will enable interoperation between many vendor's products. Note, however, that modified or proprietary protocols may still be the way to go -- while locking a user into a specific brand of VoIP product they may also provide the critical features required by that business that more standardised and interoperable protocols don't.
- Network infrastructure. While most of these handsets are designed to not require new networking switches or cables to be run (most of them have two or more in-built port switches), it is nonetheless worth your while checking locations of existing phones and ensuring that there are already network points nearby.
Also spend time checking the quality of your existing network cabling, routing, and switching to ensure that no unnecessary loops or traffic will be created when the VoIP system is added. Most handsets have two or more network ports enabling the desktop PC or notebook to be plugged in, thereby removing the need to run two network cables to each desk. The Zultys 4x4 and 4x5 handsets have a built in 4-port RJ45 switch.
1%
8%
ISP's are currently battling the broadband war. The race for customer aquisition is aggressive. What is the holy grail... VoIP or basic broadband revenue? The answer lies in the current broadband price offerings of ISP's.
The cost savings of VoIP to corporations is unquestionable and the future economic benefits of widespread adoption is inevitable. One just needs to review the developments of such products as 'Skype' over the last 12 months to arrive at the realisation of just where VoIP is heading. Companies in Asia have even commenced manufacturing 'Cisco ATA type' devices which interface with skype enabling VoIP calls from your normal PSTN phone. The future of VoIP is cemented and the war for market share is definitely on.