While there's little doubt that packet-based networks are the wave of the future, legacy networks are here to stay--at least for the foreseeable future. With significant sunken investments in circuit-switched networks, many legacy network operators are looking to marry their SS7 and intelligent networking infrastructures with Internet and other data-centric technology to expand into new revenue-generating services and geographies.
"Right now the hot area for any carrier, whether they're an incumbent or competitive, is new revenue-generating services, and a lot of the services are sitting in the ILEC networks today," says Jack Kozik, director of IN architecture at Lucent Technologies Inc. (www.lucent.com). "You can rewire the network to do Internet telephony or you can use your existing network to do it."
One example of an application that legacy network operators can offer with a few tweaks to their existing networks is Internet call waiting, where call processing still goes through circuit switches, but alerts of incoming calls appear on a pop-up screen on the subscriber's PC. "So the entire network still offers the same service, but by interoperating with PCs it extends it, and now you can route the call to voice mail, route to a mobile phone or other phone or to a voice over IP phone," he says.
In these cases, the network operator needs to interface its signaling network--usually SS7--to an IP network, Kozik explains. Specifically, a server or server farm speaks SS7 on one side to a Class 5 switch or IN layer server control point (SCP) and speaks IP to the "Internet cloud" (which could have a firewall, load balancing server or other device at the edge) on the other side.
In Lucent Online Communication Service, an Internet call waiting product, Lucent's SCP speaks SIP--a VoIP protocol--to the service's application server, adds Kozik.
He explains that within SIP are standards for how to allow SIP to communicate with the PSTN. That and other IP to PSTN signaling and IN interconnectivity procedures are being defined by the Internet Engineering Task Force's (www.ietf.org) Pint and Spirits working groups, he says. Pint has approved a draft focusing on Internet call waiting-style services; whereas Spirits is a relatively new group that's working on click-to-dial applications encompassing both the PSTN and the Internet, says Kozik.
Once a network operator is able to make SS7 to IP, that operator can then access content or services from a "service provider that may be nothing but an Internet address," says Paul Nevill, marketing manager for signaling products at Nortel Networks Corp. (www.nortelnetworks.com). That means that such network operators will be able to deploy services more quickly and without having to manage a point of control or doing programming themselves. "Carriers love this potential," he says.
Another example of how carriers can "webify" services they've been successful with--such as personal number services-- is by adding web-based provisioning, in addition to interactive voice response (IVR) provisioning, adds Kozik.
Telcordia Technologies Inc. (www.telcordia.com), for instance, is upgrading its iSCP product, which includes a service creation environment known as SPACE, to include such a web front end to allow for customer self-provisioning. Telcordia would not specify the availability of this enhanced product.
Lip Service
VXML, or voice extensible markup language, adds yet another twist for legacy operators wanting to employ IN to hook into the web, says Kozik.
The VXML Forum has defined a markup language for prompt and collect (for example, press 1 on your telephone touchpad to hear the temperature, press 2 to hear stock quotes, etc.). So a company could use VXML to define codes and link to Internet content for this. "We've always had IVR, but VXML lets you put IVR scripts on web pages. By interoperating with the web, it can let a carrier offer a business or ASP an engine for services with service logic stored on web pages. So that brings another level of service creation openness," says Kozik. "In this case, service nodes on IN add VXML engines and interfaces to the Internet to fetch VXML Internet content."
Lucent, late in 2000, was doing trials with undisclosed customers of its TelePortal product, a VXML-enabled service node intelligent peripheral. Lucent is also enhancing its entire platform, known as @udioPortal, for Internet voice browsing to enable a series of Internet voice services. "It takes you beyond legacy to do content caching and location services for mobile Internet. When you're in your car, it lets you do voice browsing," says Kozik. That new version is slated for availability this quarter.
A WINning Combination
Wireless network operators are also using their intelligent networks to tie in with Internet-related content and services. For example, Lucent is developing a service to link information in wireless networks' home location registers (the network-based devices that hold subscriber information and services) with instant messaging networks. That can include a cell phone part in a "buddy list" to enable the PC user to see where a friend or relative using a cell phone is. One possible application would be to enable parents to know where their child is by looking at his or her cell phone, Kozik says. "This is a hot topic; people are trialing it," he says.
Standards to support these types of connections are still in the works, says Kozik. One standard being proposed is called IMPP (instant messaging and presence protocol) out of the IETF. The IMPP Group still has not reached a consensus, Kozik says, so America Online Inc. (www.aol.com) and Yahoo! Inc. (www.yahoo.com)are moving ahead with a different initiative called the Presence and Availability Management Forum (www.pamforum.org). The PAM forum is an industry group that wants to define an API (application programming interface) for presence-style service creation. Lucent and Novell Inc. (www.novell.com) are the founding members of that group and Pulver.com Inc. (www.pulver.com) is orchestrating the effort.
"It's exciting that it builds on the legacy and that it's what users want--Internet users and mobile users," says Kozik.
Beyond web enabling existing services, operators of wireless or wireline legacy networks can move their signaling and/or intelligent nodes onto the Internet to enable them to expand their network footprints more quickly and cost effectively, says Paul Miller, vice president of packet telephony at Tekelec Inc. (www.tekelec.com).
"The IP7 Secure Gateway product from Tekelec bridges the PSTN and the next-gen network," says Miller. "It also uses IP networks to carry traditional PSTN signaling, so it's not only talking to softswitches, but it provides all the advantages data offers." Qwest Communications International Inc. (www.qwest.com) has deployed the product to move its home location registers, virtual LRs and wireless asset management to IP/packet networks, installing secure gateways and applied IP connections on one side and PSTN on the other side of those network assets. This allowed for lower transport costs for Qwest's SS7 traffic and extended the reach of its signaling network because SS7 requires dedicated links to each point the carrier wants to access, says Miller.
He says the reliability issue of putting signaling for PSTN lifeline traffic over a packet-based network is a concern, but that carrier can get a SLA data connection from the IP service provider from which they lease transport.
Meanwhile, groups such as the IETF's SIGTRAN body are working to further address the issue. Nortel's Nevill says SIGTRAN has put together a whole group of recommendations for standards about how to map SS7 to IP, two of which are in a request for comments stage and others that aren't as far along.
A Third Party
The traditional intelligent network is also expected to evolve from the standpoint of the third-party developer, according to Bichlien Hoang, general manager for network intelligence consulting and engineering in professional services at Telcordia.
Of course, the goal of IN from the beginning was to decouple new services and features from Class 5 switches so network operators wouldn't have to wait a year for a new software switch release. Rather, they could add new services and features on their own or with the help of third parties.
"That is one area where IN has fallen short," says Hoang. "What we are waiting for is some standards, which have not progressed as quickly as we wanted."
But Telcordia is working with a consortium of other vendors to create API standards around Sun Microsystems Inc.'s (www.sun.com) JAIN and Java technologies. The JAIN consortium is trying to build Java beans so developers can create services on any service creation platform and can run them on any platform, says Hoang. "The work has been progressing pretty well to map SS7 to Java. The next step is to work on a set of standard Java beans to create services," she says.
A European consortium of vendors, called PARLAY, is also looking at ways to standardize APIs for more platform- independent operation, she adds.
But Miller questions how well suited Java and other new protocols are for public networks like the PSTN.
"With Java you will sacrifice performance--response times and call processing ability. These technologies are not meant to scale. PSTN, meanwhile, has dumb terminals and high capacity elements. In a model where the network is intelligent and there are elements built for that, Java will have a tough time competing."
Java, JAIN and XML have promise for the PSTN when used as service creation protocols, he says. But he has reservations about using these protocols to actually run high-end IN-based services like caller name or local number portability on a softswitch-based platform.
