In all such scenarios, the VoIP call is passed along with- which can interact with them. Second, you need a fairly high out conversion to the PSTN and its per minute charges; the level of security; and probably the most important part of call is consequently peered through to another service provid- security is identity. If you’re communicating with somebody er or enterprise as a “pure” VoIP call. (This is why Junction using various modes, you must be sure that you’re communi-Networks, for example, refers to their VoIP Exchange as a cating with the correct person.”

“PSTN avoidance platform.”) “If federated systems don’t deploy right from the start with

Daniel Dearing, VP of marketing at NexTone, makers of strong cryptographic identity then, unfortunately, we’ll be fol-session border controllers, says: “Enterprises moved to IP lowing the email path of having no identity and, hence, prob-PBXs to reduce the costs in the campus environment and lems such as spam and spit will take off,” says Johnston. “If convergence for them is simply another way to save money such things had happened in the early days of federation and on things like long distance. They can peer with early VoIP peering it would have caused people to just pull the plug and adopters on the service provider side who typically are very say, forget it, let’s go back to the PSTN. Amazingly, some peo-focused on providing long distance and other hosted services, ple are talking about implementing federation without strong so it’s a ready-made partnership that can reduce costs.” cryptographic identity. I’m surprised at that–the lessons from

“After all, the original idea behind VoIP peering was simply email are very clear.” reducing the costs of long distance charges,” says Dearing. “At “Third, there are some interoperability issues today,” the VON show we announced a Japanese customer, Shinsei says Johnston. “Unfortunately, not everyone supports SIP Bank, doing just that. They’re a good example of what’s hap- and SIMPLE, so you need to interoperate amongst multiple pening in the financial verticals. Such big organizations are systems, some of which are still closed, which you can only spread out over a large geographic area, so there are many op- enter and leave via the PSTN.” portunities to save money using peering for VoIP and data.” “Fourth and finally, you need a fairly high degree of system

“Many of these early adopters use our session management manageability,” says Johnston. “A favored model is federation technology to enable peering not only with other enterprises based not on bilateral agreements, but rather a sort of multilat-to create things like extranets,” says Dearing, “but more im- eral or loose clearinghouse-type model. To implement this, you portantly to interconnect with a large number of service pro- must have good management controls over who you’re willing viders that can furnish long distance connectivity to various to communicate with, in what modes, and who you’re going parts of the world where a big enterprise may have offices. to share such information as presence. Some existing systems Most enterprises deal with one or two service providers, but which can be federated unfortunately don’t seem to have that we can help them manage working with 10, 20 or 30 provid- full set of manageability tools. To make federation and peering ers, which would normally be a complex affair.” work, enterprises need a lot of very granular control over what

“For secure traffic, the easiest way to do peering is by ex- they do and how much interconnection is done over IP.”
tending a VPN,” says Dearing, “but in some cases an enter- “That said, I do think that federation will definitely be pop-
prise simply wants voice traffic, chat or IM extended to an ular,” says Johnston. “The main driver for enterprises has less
employee working at home or some other trusted entity. The to do with cost, because PSTN call rates continue to plum-
Internet can be used for this provided you have a secure de- met, and it’s hard to justify federation and peering solely on
marcation point between the Internet and your private net- VoIP savings. Still, if you have a small or medium-sized en-
work. The Internet is often treated as a non-secure backup terprise that’s extremely geographically dispersed, then you
to a private line. However, you still want to ensure that the could probably justify it on cost, especially if your locations
peering points are secure no matter what. That’s where our have very high PSTN rates. But more and more peering and
session border control technology comes into play.” federation will be about the additional services. If you’re fed-
erating for VoIP then you can also federate your presence, IM
The “Presence”of Voice and other services. Do it with a standard like SIP, and you can _{achieve integration with various applications.}”

Dr. Alan Johnston is co-author of the new book SIP Beyond

^{VoIP and is CTO of Tello, a new company that provides} real-time communication sharing or “federation” services for ^{Standardizing Peering and} _{enterprises. Federation}

“Tello doesn’t just deal with VoIP, but also presence, instant “Two big standardization efforts going on right now related messaging, and various other types of communications,” says to peering,” says Tello’s Johnston. “In the SIP Forum there’s a Johnston. “We believe the driver for enterprise federation project called SIP Interconnect and it’s basically about defin-won’t so much be about VoIP and cost savings, but instead ing the SIP interface between an IP-PBX and a service provid-will be about additional services, the use of presence and in- er. Some people have always assumed that you need a service tegrating presence into applications and business processes. provider which has to handle the signaling and media, and As my book’s co-author Henry Sinnreich says, ‘Presence is the we’d have to essentially replicate the PSTN model. But with dial tone of the 21st century’.” SIP you don’t have to do that as long as you have security,

“Enterprise peering and federation is a tricky thing to do, interoperability and manageability services.” and there’s actually very little of it happening today, from what “There’s also a new SIP Working Group in the IETF’s opera-I’ve seen,” says Johnston. “There’s basically four big pieces tions area,” says Johnston. “It’s less about protocol extensions to solve to make a system work. First, you need a discovery than it is about real-world recommendations regarding how mechanism to determine if the people you’re trying to reach SIP can be used over the Internet, rather than how it can be are IP-enabled, SIP-enabled, and what the various modes are used in, for example, a closed island or a walled garden net-