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VoIP is all Business at VON

by Andy Oram

Voice over IP is in an early stage: mimicry. Like many new technologies, it has started its economic life by reproducing familiar services and features from the established products it is trying to replace; in this regard, VoIP providers promote PBXs, call routing, automated voice response, and other things businesses are used to looking for.

That's my impression from checking product announcements and session topics in September at VON, the major VoIP industry show. VoIP has a benefit to deliver right now, but it's being realized mostly in corporate communications. VoIP's potential cost savings are obvious when a business considers running all of its calls over the same IP network it set up internally for data, as well as over a phone line to its internet provider (which could be its phone company).

I think the big advance in internet communications will come eventually from a merger of applications such as sensors, audio, video, and groupware. Voice will be just a built-in means of interfacing with devices over a network, and people and applications on those devices. This is quite a way off.

But a lot of interesting things were happening at VON.


The conference moved this year to the new Boston Convention & Exhibition Center, so I got to see this building for the first time. I noticed that the staunch puritans among Boston's city planning department ensured that visitors arriving by public transportation would have to cross a long bridge to reach the building--a memorable effect, I'm sure, in a raging snowstorm. But once you get to the center, you can enjoy wonderful views of a city that actually looks pretty nice from the southeast, as well as a more upbeat decor and convivial layout than the Hynes Center offers.

Mesh Networking Commercialized

Let me start with a couple of companies offering products or infrastructure that I thought showed some of the exciting new things we could do with VoIP. Neither of these companies are really offering VoIP; rather, they're at the conference because VoIP could make use of their offerings.

Mesh networking has been a passion of the Pringles-can WiFi crowd for a decade, as well as a fixture of experiments such as sensor networks. But its viability as a mainstream technology--and one that generates revenue for vendors, to boot--is demonstrated by the story of Firetide. VP Barbara Cardillo spoke to me about their products and who's been buying them.

The core technology is a wireless mesh network made up of several hubs, using the same standard protocols to interconnect that they offer to customer equipment. Currently they employ 802.11b and 802.11g, but they can be upgraded in the future for another standard, such as WiMAX.

Hurricane Katrina has led to well-publicized discussions about the serious barriers that incompatible communications devices put up to effective disaster response; governments are consequently getting very interested in WiFi mesh solutions such as those offered by Firetide.

The products are a range of hubs with two antennae and a number of Ethernet ports to which one can connect not only phone lines to the internet, but devices such as video cameras.

And video cameras (such as those for surveillance) are one of the most popular applications of this mesh network. The ability to share images from cameras shows that WiFi bandwidth is pretty good. But VoIP and data networking are also popular; warehouses and educational institutions are among the main customers, along with more familiar ones like municipal networks.

Some companies are already deploying protocols similiar to the WiMAX standard that is currently being implemented and tested. One example is TowerStream, which uses Aperto equipment to serve customers in Boston, Chicago, and New York.

TowerStream calls one of its most popular offerings "five for five," which stands for 5Mbs for $500. (The 5Mbs refers to the actual TCP output, free from any overhead eaten up by wireless protocols.) Since a T1 typically costs about that amount and offers only 1.544Mbs, this is very competitive in terms of cost.

However, the real benefit of TowerStream, made possible by Aperto's protocols and eventually by 802.16, is differentiated traffic. The TowerStream "five for five" service guarantees 1.5Mbs (the same as T1), duplex, using the CIR (Confirmed Information Rate) protocol that will be standard in 802.16. The rest of the "five by five" is 3.5Mbs for best-effort service that occupies the blank spaces left by the guaranteed service. So customers can simultaneously use the service for voice (set up with the standard SIP protocol) and for web traffic, email, etc. without disrupting the voice transmission.

The 1.5Mbps-guaranteed TowerStream service, like a traditional T1, can reliably--without oversubscribing--carry 15 VoIP phone calls simultaneously, where each phone call requires 90Kbps and is sent without compression. One can imagine supporting 45 users if--as cell phone providers often do--one allows a three-to-1 oversubscription.

The network is designed for line-of-sight service, but in practice works very well without line of sight. In fact, the company has service in cities with lots of buildings and potential noise from other spectrum users. Some customers get service 12 or 13 miles away from their POPs.

3G Enables

I sent video mail at the Glenayre booth. What's video mail? VP Kelly Bevan demo'd it by calling one phone from another phone and leaving a message that contained both voice and video; if the receiving phone is capable of displaying video, it shows us talking as well as playing what we say.

This may not sound like a great enabler or productivity enhancer, but it's catching on in Europe and Asia because people see it as cool. This simple application shows that advanced networks spur innovation. Bevan says phones are "just in the embryonic stages" of developing internet applications, and that video conferencing (for instance) will be in demand.

But the note of alarm here is that Glenayre could not show off its new application in North America on a cell phone, as they do in the rest of the world. At VON, they mocked up a cellular connection using IP. This is an illustration of how far we lag behind.

VoIP in the Home

There was some talk of home users at VON, but the vendors' energy was clearly not there. VoIP is not yet a mass phenomenon in the home market, at least in North America. And in fact, people with VoIP in the home tend to complain about quality. Is the problem meager provisioning of network bandwidth by the DSL or cable company? Not according to Peter Nilsson of i3 micro technology. He says he's spent lots of time configuring home networks for VoIP, and it's not easy to do well. It may be necessary, for instance, to set up separate virtual LANs for voice and data.

But ADSL, especially the newer ADSL2+, has plenty of bandwidth for voice and video. ADSL2+ promises 28Mb/s downstream in theory, and delivers about 15Mb/s. This should be enough for three video streams. As copper performance goes up in speed and video compression brings bandwidth requirements down, fiber to the home becomes less necessary--at least until new applications such as videoconferencing come into demand.

So a lot depends on configuration. Nilsson thinks many vendors spend three hours per year doing customer service over the phone with each customer, an investment that can take five months to recoup. Truck rolls are even more expensive. He boasts of the remote configuration designed into i3's customer-premise equipment, which takes the matter right out of the customer's hands; in fact, the customer often doesn't even realize something was done to the box to fix a bug or enable a new feature.

Firming Up the VoIP Foundation

As I pointed out, VoIP is evolving a bit differently from some familiar disruptive technologies such as the Web, instant messaging, and open source software. The latter went through a big grass-roots phase, becoming popular with individuals before businesses. VoIP has its early adopters, certainly (particularly among people making international long-distance calls), but it looks like it's on a trajectory now from big enterprises down to individual users.

Therefore, VoIP vendors are very concerned with robustness and reliability; they have to promise uptime just as good as the well-established circuit-switched phone network. Easy administration is also a concern for their enterprise customers.

So I wouldn't be surprised if the focus of VoIP slides for a while from innovation to standardization. Or more likely, hackers and academic experimenters will continue to develop new applications, but they won't be as visible at a show such as VON, just as a lot of the cutting-edge experiments with Linux are hard to find at the LinuxWorld trade show.

At VON last year (documented in an article from that time), everything I attended was about protocols and interoperability--technical concerns. This year, I've noticed a lot more interest in scaling up deployments (sometimes to the county level), remote management with self-administering gateways, and other such enterprise concerns. Many speakers announced the dominance of the SIP protocol, which is a bet on safety and familiarity. One vendor said that standards continue to evolve, but not so much through the invention of new ones as through extensions to standards that are known to have something to offer, notably SIP.

The recent eBay/Skype deal illustrates in a rather oddball way the entry of large companies into the VoIP space. More typical was the joint venture between Intel and Digium--the company founded by Asterisk creator Mark Spencer--to make Asterisk one of the drivers on Intel telephony products.

Security Sucks All Over Again

Just as with web database applications and other new programming environments, VoIP has to go through a familiar period of fixing up security. Set aside worries about sophisticated denial-of-service attacks: the immediate danger is in garden-variety buffer overflows and other common programming errors.

I talked to Ejovi Nuwere, who runs SecurityLab and makes a living auditing VoIP products for security. To show how we can't ignore lessons from the past, he examined several open source SIP implementations and found at least two major security vulnerabilities in each, reporting on them at the recent BlackHat conference.

The reasons he cites for security problems are also depressingly familiar. Firms developing VoIP solutions are small and have few resources to devote to coding; furthermore, they concentrate on features and equipment instead of robustness and security. Often they base their software on the open source implementations just mentioned, as a quick way into the market. (At least they won't be any worse than the rest of the vendors doing the same thing.) Managers may come from a public switched telephone network (PSTN) background and have a false sense of security, because they're used to a closed network.

Ways to capture voice and convert it to text have also been feasible for some time, an enabler of many good applications but also a boon to malicious snoopers.

Performance Monitoring for Quality of Service

Along with security, another province explored by several companies at VON was performance monitoring. I talked to Alan Clark, who worked at British Telecom and developed some important standards, such as V.42bis compression, while on his way to founding Telchemy to create monitoring software for VoIP and video over IP.

Many problems with these services are naturally transient; they depend on what somebody else along the route might be doing at the moment. Telchemy monitoring software has a small footprint and can be inserted practically anywhere, either into dedicated hardware or a network device doing the transmission. It measures packet loss and jitter, along with some other statistics that reflect subjective user experience.

Compared to voice, video is even more challenging because:

Changes Proposed at Layers 1 and 2

I had an intriguing short talk with David Bassett of Vocal Technologies. Their latest product can provide VoIP for a whole house of phones for about $100. The main component plugs into a DSL or cable modem, while other components connect individual phones to phone jacks and create an Ethernet over the internal phone lines.

Bassett found that Layer 1 and 2 protocols create problems for VoIP and could be improved to retransmit faster in case of collisions. He has submitted some ideas to the IETF for allowing trade-offs at these low layers between efficiency and fairness, ultimately cutting way down on packet loss for VoIP.

Other Corporate Developments

Of course, I grabbed the opportunity to talk to Mark Spencer, inventor of Asterisk and president of Digium. Continuing the mission of supporting all voice protocols through Asterisk, they've made architectural improvements to the most recent version to allow for more flexibility and make it easier to incorporate support for protocols.

New SIP capabilities and Bluetooth support are specific recent additions, with patches been written to support encryption through TLS. They also support some carrier protocols for high-density deployments. Their AGI (similar to CGI) broadens the number of programmers who will be able to write interfaces to Asterisk.

Some of the features that can make a difference in people's phone experiences include strong support for presence (as one has in instant messaging) and DUNDi Core Routing, which enables a peer-to-peer connection model. A General Peering Agreement makes signatories agree not to abuse peer-to-peer connections.

What are they not working on? Well, Asterisk hasn't incorporated hand-off mechanisms such as cellular phones have, but that isn't a liability, because VoIP is not yet employed through a network of towers like cell phones. Spencer is following 802.16 (WiMAX) development, but it seems expensive enough at this point that they don't need to worry about supporting it.

I talked to Ed Camarena at Veraz Networks about their interfaces that make it easier to port applications to VoIP and to make new devices compatible. In effect, companies are replacing the PSTN and non-IP cellular networks piece by piece; Veraz products provide common interfaces that are appreciated by companies that are merging or trying to quickly support new devices.

Policy Impacts

Policy issues have made such a mess of telephony for so long that VoIP can remain free of them only by setting up an independent network, and that's what I think ultimately will happen. Providers are hell-bent to connect to the public telephone system, but the deck is stacked and the headaches are enormous.

Senator John Sununu of New Hampshire came to VON, as he did last year, to deliver a keynote promising legislative support for VoIP. Like Michael Powell (who also gave a keynote last year, when he was still chair of the FCC), Sununu is a conservative with a dual and perhaps contradictory approach to economic policy. He likes new, innovative businesses with lots of energy behind them, and wants to remove artificial barriers to their growth. But on the other hand, he does not challenge the right of older telephone carriers to extract the maximum profit they can from their own networks, even when doing so places barriers in the way of new entrants.

In discussing the initiatives in Congress, he focused rather obliquely on spectrum reallocation and said nothing about a more relevant bill recently considered in the House Energy and Commerce Committee, reputedly an "update" of the historic 1996 Telecom Act. This bill would legislate several of the requirements that regulators have been trying to enforce on VoIP operators: payment into the universal service fund, emergency 911 services, and so on. Sununu's contribution to this debate was to indicate that VoIP providers had better comply with these regulations, which import all sorts of assumptions from the circuit-switching world to VoIP.

Brad Templeton, chairman of the Electronic Frontier Foundation, asked Sununu to support opening more spectrum for unlicensed use, which is the environment in which WiFi has flourished. Sununu made the interesting reply that providers seem to find as much bandwidth as they need for their use of unlicensed spectrum, which is limited to local area networking because unlicensed spectrum comes with power restrictions to prevent interference. He felt that other areas of spectrum would be more fruitful if licensed to providers who can exploit it at higher power levels.

Claims of abundance for unlicensed bandwidth may be borne out by earlier interviews in this article. But one can always argue that having more resources leads to new applications, and that unlicensed use should not be constrained forever by the historical accidents that led to its current bandwidth. (And to his credit, Sununu said he was open to hearing about potential uses for a broader spectrum.)

In response to other questions, Sununu:

As observers have been warning recently, the U.S. is really not adopting high-bandwidth networking the way a country would if it were serious about promoting an information economy. Hardly anyone is laying the groundwork for the converged applications I mentioned at the beginning of this article. VoIP vendors are going to have to continue their slow progress converting users one office at a time until something creates a big new opportunity for new applications.

Andy Oram is an editor for O'Reilly Media, specializing in Linux and free software books, and a member of Computer Professionals for Social Responsibility. His web site is www.praxagora.com/andyo.

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