The VoIP world has something for everyone, from hardcore do-it-yourselfers
to folks who would rather hire everything done. There are also a lot of in-between
options, so today we’re going to look at one that applies to a wide range of
circumstances and offers what I think is a lot of bang for the buck: using a
Comtrend has released a new small business and enterprise VoIP gateway, the
CT-814M, which takes a different approach from the usual VoIP gateway device.
Andrew Morton, the Vice President and General Manager of Comtrend’s North American
division, was kind enough to give me some background on the CT-814M and where
it fits into your network architecture.
Smart networks, smart endpoints
In the beginning, the telephone network was smart, and the telephones were dumb.
They only did one thing: initiate and receive phone calls. All the heavy lifting
went on behind the scenes. Then came the VoIP revolution, and the humans were
left behind. Well not really, but using IP networks for telephony has finally
made advanced services like videophones, conferencing, multiple devices per
user, and private VoIP WANS manageable realities. It’s also made protection
from eavesdropping possible by using ordinary IP network tools such as VPNs
and public-key infrastructures, though these are limited in scope, and there
still isn’t a universal, lightweight, transparent encryption protocol.
Splitting the workload
VoIP gateways are not new; there is a large number of brands and models to choose
from. Typically you can choose from features such as FXS/FXO interfaces, Ethernet,
T.38 support for faxing, 911 support, PSTN fallback, T1/E1 interfaces, multiple
codec support, jitter buffer and echo cancellation, QoS and packet filtering,
conferencing, and so forth. They are good, cost-effective devices that solve
a number of problems, with SIP
NAT traversal and QoS at the top of the list.
Using a standalone VoIP gateway removes a significant processing burden from
your iPBX server. Asterisk was invented back when x86 PC hardware was considerably
less expensive than telephony gear, so it was cost-effective to use an Asterisk
box as a PSTN gateway via Digium’s own FXS/FXO interfaces, or those of competitors
such as Sangoma and Rhino. But that cost advantage has disappeared, so your
iPBX box can be just an iPBX, and not do double-duty as your PSTN interface.
Ideally you will have a dedicated Internet line for your VoIP. Putting a VoIP
gateway between your VoIP server and the Internet, on its own dedicated Internet
connection, makes it a lot easier to administer and secure, and you’ll get better
call quality. You’ll also avoid conflicts with DHCP and DNS—VoIP servers that
support auto-provisioning phones include their own DHCP/DNS servers, so trying
to manage these in harmony with your existing nameservers gets complex. It’s
easier to dodge the problem entirely by putting your IP phones and servers on
a separate network.
Anyone who wants to manage their own iPBX and network needs a broad skillset:
system administration, telephony knowledge, and network administration. Thanks
to Asterisk and the VoIP revolution, VoIP do-it-yourselfers have been given
unprecedented control and flexibility over their telephony. But it doesn’t hurt
to look at what tasks you can delegate, and this is where the CT-814M fills
a useful niche.
First some specs: The CT-814M is a four-port PSTN gateway that supports four
analog phone lines; it includes four Ethernet LAN ports, an Ethernet WAN port,
a stateful packet inspection firewall, content filtering, echo cancellation,
jitter buffer, 802.1P and Q QoS, and a batch of calling features such as call
waiting, call blocking, fax/modem passthrough, click-to-dial, and various other
Rolling fewer trucks
Moreover, it comes with complete remote administration capabilities, including
remote firmware upgrades. While anyone can buy one, the CT-814M is targeted
more at ILECs (Incumbent Local Exchange Carriers) and CLECs (Competitive Local
Exchange Carriers)—from the customer’s perspective, the local telco. The
idea is to offer the customer more bundled services with full remote management
capabilities. It’s similar to ordering a T1 line, and haivng your telco bundle
a router into your package. They it install it on your premises, and configure
and manage it for you. The only time the telco needs to get a truck to your
location is to install the device; after that it’s managed remotely.
There are several advantages to this approach: You can probably negotiate
a good deal with your telco, and you have technicians from the mother ship taking
care of the gnarly bits. Then all you have to do is manage your VoIP server,
and this can be any server you care to run—Asterisk, Trixbox, SipX, PBX in a
Flash, or any of the many others that we have to choose from.
An even bigger advantage is call quality. By dealing directly with your telco, you can be protected by an
SLA (Service Level Agreeement), because the telcos have complete control of their wires. Resellers like Vonage and Skype do not, so you are at the mercy of random events on the Internet. The telco benefits as well, by offering more services and controlling the device remotely, which saves a ton of money and time.
VoIP is growing up
If your business depends on reliable phone service, don’t bet the farm yet on
VoIP—you still need the PSTN both for reliability and call quality. I’ve had
way too many conversations over bad VoIP and cell connections, and I don’t care
how cheap it is when most of the conversation is “What? Are you there? Hello?”
It’s not like the telcos are going to disappear anyway—who do you think maintains
the wires the Internet travels on? And no matter how much we tuff old do-it-yourselfers
resist, I think the future of VoIP is hosted services. Just like today’s telephone
services, only far more advanced and cheaper.