Internet telephony is very much the holy grail of networking. Running voice and data communications over a single network offers self-evident savings in telephone bills, administration costs and equipment costs. In addition, such a converged network is "future-proofed" for such emerging technologies as streaming video and e-commerce. Yet, despite these obvious advantages, it has remained an elusive goal.
Early solutions, such as 64K ISDN data networks that were capable of interfacing directly with existing PBX telephone systems, proved unreliable and, therefore, unpopular. Investment in PBX technology, furthermore, has not managed to keep pace with the growing data transfer requirements of businesses.
Meanwhile, investment in IP technology has blossomed -- fuelled by the explosive growth of the Internet. This growth has made the goal of voice over IP both possible and practical. Integrators such as Queensland-based Sundata (a Cisco partner) report genuine and considerable cost savings to customers, which has the obvious benefit of increasing satisfaction and customer loyalty.
But voice is no longer the only goal, as the multimedia-oriented Internet has led to the creation of newer, more bandwidth-hungry applications. Alan Pettigrew, director of Portfolio Marketing at Nortel, calls IP telephony "the second wave of e-business". He says it is "the enabler of all the multimedia applications that are coming". The goal now is to maximise the integration of disparate applications over common networks, while also maximising the value customers gain from their purchases of network bandwidth.
IP for the network
Cisco's approach is called Architecture for Voice, Video and Integrated Data, or AVVID. AVVID is a complete IP-based LAN/WAN architecture, scalable from a small business to a larger organisation incorporating multiple offices. Telephones (whether actual handsets or integrated software phones on PCs) are treated as endpoints on an IP network, and calls within the network are treated as IP packets. Only when calls need to cross outside the LAN/WAN do they get switched to traditional telephone calls - invisibly to the caller. This saves dramatically on call costs. For integrators, it is a strong approach because IP is the underlying protocol for the entire network -- the network designer can employ Point-to- Point Protocol (PPP), Frame Relay, Asynchronous Transfer Mode (ATM), digital subscriber line (DSL), Synchronous Optical Network (SONET), or whatever IP-compatible technology is most practical for the customer.
3Com has a complementary ap-proach to voice and data integration, which it calls CommWorks. Actually an end-to-end platform, CommWorks emphasises a multi-tiered approach to the transition to a converged environment from legacy technologies. A "media processing" tier integrates multiple traffic types across multiple access networks, enabling seamless interoperability between IP, PSTN, cable and wireless networks. A second, "signalling, control and management" tier mediates protocols, enabling seamless transmission of network traffic across disparate networks. Finally, a "service creation" layer enables service providers to integrate existing service control points with next-generation packet networks. This reduces development costs.
There are, of course, two sides to the convergence of telephony and data communications. Not only are networking giants en-hancing their offerings with telephony, but several of the big players in telecommunications are now recognising the advantages that IP networks can offer their telephony customers. Two such companies are Alcatel and Nortel.
Alcatel, for its part, offers the pleasantly monikered DAVe, short for Data And Voice E-commerce. The philosophy behind DAVe is "transparent convergence" -- wherein both the combination of voice and data, and the migration process itself, are invis-ible to users. The traditional PABX system is replaced with an IP server (the 4400 IP PCX) that includes voice processing application software. The server senses the level of the network's sound quality and, if not satisfactory for voice calls, transfers the call to a traditional circuit.
Nortel also offers an end-to-end IP telephony solution, tailored to the needs of small to medium-sized businesses. Although lacking a punchy acronym, Nortel's so-called "Business Series" delivers IP communications, integrated voice and data e-commerce applications, IP routing, Web-browser management, a choice of circuit-switched or IP tele-phony (or both), and Quality of Service (QoS) on the LAN and WAN. The Business Series consists of Business Communications Manager -- an all-in-one platform for small business IP telephony, messaging, call centre and IP routing communications -- and Business Policy Switch, a new product that ensures QoS.
While many of the benefits of IP tele-phony can be and indeed are realised already, much of its promise - computer/telephony integration and video, for instance - is still distant. Increased bandwidth is an obvious solution, and an inevitable outcome these days. But the real winners in this technological convergence will be those resellers and integrators who can tailor solutions to their customers' needs, optimising the networks they already own.
Alan Pettigrew, director of Portfolio Marketing at Nortel, views channel opportunities in IP telephony as "open-ended". He argues that "the opportunity for the channel isn't just in hardware sales -- there's going to be an awful lot of integration" in terms of applications and building feature sets into customers' existing purchases. He also cautions against an "all or nothing" approach: "We don't believe that this has to be a wholesale upgrade -- [for instance] throw out your old networks and PABXs and put in this new equipment. Our view is that you can take your existing equipment and start evolving it."
It's about quality
When the IP network becomes congested, packets fight with each other for a place in the pipeline. This can mean lengthy delays, dropouts and even failed downloads. Such problems, when translated to telephone conversations, are highly unsatisfactory. Bandwidth has always been the barrier to effective IP telephony, but even with today's gigabit networks, packet clashes can still be a problem.
The solution is called Quality of Service (QoS). Basically, QoS means that packets containing voice information receive higher priority than packets containing only normal data on the network. This ensures that, when delays happen, they are much less likely to affect the quality of telephone calls.
3Com NBX 100
The 3Com NBX (network business exchange) combines a telephone system with a local area network (LAN). This means employees can use voice applications, access the Internet and use LAN applications simultaneously with a single cable to their desk.
There is a full set of PBX features, with unified messaging automatically delivering voicemail to users' e-mail inboxes as .wav files.
Computer Telephony Integration (CTI) provides quick access to customer information on incoming calls, allowing for faster call handling and improved customer service. Browser-based administration, either via the Web or through 3Com's proprietary NetSet, lets administrators perform moves/adds/changes.
3Com: 1800 644 606
Cisco Catalyst 4000
The Catalyst 4000 family of switches support high-density 1000/100Mbps switching with advanced multilayer capabilities, IP routing, voice gateway functions and voice network services. They also include advanced new management features, such as phone discovery, extensive QoS support and auxiliary VLAN.
Cisco also delivers management tools enabling network visibility and control. The voice modules provide extended management, statistics and status information for voice traffic. For example, users can query to see how many calls are active, and also gather management data about these calls, such as the source/destination module, port and IP addresses. Centralised management is provided through CiscoWorks, and the voice network services functions are administered from CallManager.
Cisco: (02) 8448 7100
Alcatel OmniPCX 4400
The Alcatel OmniPCX 4400 IP-based PBX manages communication according to service type, and achieves cost savings through time-based selection of the best-priced network. This increases network choice -- voice over IP, frame relay, ATM, or even traditional circuit networks.
Through packet voice technology, the OmniPCX 4400 manages QoS -- the integrated IP gateway monitors voice packet irregularities and delays, and if the quality becomes unacceptable, communication is re-routed via another network (the public ISDN network, for example). At the same time, it maintains a complete set of services, whatever the network infrastructure.
Alcatel: (02) 9699 0044
Nortel Business Communications Manager
Nortel's Business Communications Manager supports applications such as help desks, unified messaging and message networking. It records call details for efficient logging and can act as a centre for fax-on-demand, fax messaging and fax overflow. As well as voice over IP, it has "fallback" support for PSTN telephony.
Nortel Networks: (02) 8870 5200
Nortel Business Policy Switch 2000
The Business Policy Switch is a stackable 24-port 10/100 Base-T Ethernet Layer 2 switch that provides stackability, high-speed uplinks and Layer 3/Layer 4 packet classification, prioritisation and QoS. The switch features IP classification, prioritisation and traffic management that guarantees network availability for applications such as IP telephony and streaming video.
Nortel Networks: (02) 8870 5200