The proliferation of networking has paved the way for the development of visual, audio and data technologies the likes of which were once only envisaged in sci-fi movies. Many external old-world verities remain with us — for the moment anyway — such as that people continue to be organised in common places of work. Increasingly however, work stations are now invariably equipped with a PC or equivalent, are integrated into local networks and offer access to the world at large via the Internet. People need and want to be able to talk to each other and the outside world.
Since most networks now share TCP/IP with the Internet and all sound can be digitised, voila! — Voice and Data Convergence and Voice Over Internet Protocol (VOIP) or IP Telephony. You’ve been hearing about it.
The other hot topic in networking today is the use of wireless, which has come on leaping and bounding (well, meeting some market success) since the 1999 ratification of the WiFi or Wireless Ethernet IEEE 802.11b standard. Industry sources in Ireland now say that a wireless component is at least considered for most new LAN specifications or upgrades today. Its actual take-up is still limited, but we are talking hundreds of enterprises rather than dozens.
Both are sexy technologies to liven up our LAN lives, but clearly convergence is the most important right now. Almost all authorities are forecasting that we will move almost all telephony to digital, IP-based networks (public and private) before the end of this decade. Having said that, IP telephony most certainly still has Quality of Service (QoS) issues.
‘We really still cannot guarantee QoS assurance from end to end,’ says Dermot Woodgate of Cara, possibly Ireland’s most experienced network design and implementation house. ‘But it certainly works and for the most part works very well,’ he adds.
‘The first requirement is a thorough audit of existing network infrastructure, because IP telephony puts strains on many elements. Yet many Irish businesses have upgraded their networks in recent years, switches have taken over from routers and generally there is lots of bandwidth.’
Elements
The three elements of IP telephony on the LAN are:
• The end device or handset, usually an IP phone set which looks and performs for the user just like a smart PBX unit but is rather more expensive at up to perhaps EUR375 a pop. The alternative is a ‘soft phone’ using the PC with a headset for mike and earphone — fine for some situations, impractical in others.
• The box of tricks that replaces the PBX at the centre of the network, which Cisco terms a ‘Call Manager’ — as good a generic term as any. It is essentially a voice file server with all of the smart telephony features in software, from adding new users to intelligent call routing. Often a second box will offer fail-over security. It is separate from the network data server(s) and will also have a gateway to the phone company, analogue or ISDN.
• The LAN infrastructure, with the most important points being plenty of available bandwidth and voice-enabled Ethernet switches. Power to the handset over the gigabit Ethernet LAN cabling is now standard.
The snag that besets voice on data networks is easily stated but needs smart technology to cure. In a data network, everything is packet-ized and the digital packets are duly labelled and reassembled as it were at the point of next use. All networks have built-in error correction and many packets may be re-sent because something went wrong. All of this is transparent to the user and in any event we are used to time lags when we do anything on a computer.
In fact data seldom needs perfect realtime because it is not accessed or displayed with realtime urgency. But voice traffic is different, because the human mind and ear are acutely sensitive and a few milliseconds of inconsistent timelag will ruin the quality for us. In network terms, this means that voice traffic has to be tagged and prioritised as such all the way. So it has to be managed differently from data but over the same infrastructure. Hence the need for the dedicated IP telephony server or ‘call manager’ and voice-enabled switches.
If you have a smart networks infrastructure in place, IP telephony is now regarded as a genuine option. It is more expensive initially than its PBX rival, so the vendors tend to use Total Cost of Investment arguments over five or ten years relating to the maintenance and service costs associated with PBX. But in practice it is, according to most sources, it is the ease of management and features of IP telephony that appeal to those users who have taken the plunge. You do not need an engineer to set up a new user or implement rules-based features like ‘overseas but not 1550 or 1890 numbers.’
Outlook from within
Ray O’Connor, 3Com Sales Manager, is confident enough to assert unequivocally: ‘Our LAN telephony product has no QoS problems. It relies on nothing more than the physical network, so if that is designed and managed properly there simply are no issues.’
3Com now has 15 sites in Ireland and 200 in the UK, which contrasts with 11,000 in the USA. He points to the Athlone IT and The Helme Partnership in Dublin as IP telephony reference sites, with case studies on the web. ‘The biggest market issue in many ways is the IP hand set and its cost – over EUR300 from any vendor. But because it is in many respects a mini-switch the manufacturing costs are such that the price will not come down in the shorter term.’
But convergence is not just about IP telephony — in fact many of the real life uses that are proving popular and valuable involve video.
‘More and more organisations are deploying video content over their networks,’ says Neil Wisdom, director of LAN Communications, now part of Esat. ‘Internal training is becoming a big application as in fact are other forms of internal communications like speeches, briefings and so on. Multinationals will often send such content round the world, with various types of ‘content delivery engines’ caching locally to let users draw down on demand.’
Videoconferencing and collaborative working are also important areas. New advances in technology, Neil Wisdom points out, have got over many of the network problems these applications can cause. ‘‘Gatekeeper’ software for instance enables users to apply for and be assigned protected bandwidth for real time activities like video collaboration. The Tipperary Institute has two campuses in Clonmel and Thurles completely linked on a 155Mbps connection that allows full two way video — a lecturer can take live classes in both centres simultaneously and students can draw down recordings of that lecture at any time later.’
But many video applications do not need real time network priority. Streaming is by definition buffered, so data signal interruptions do not affect the viewer.
‘In fact it is less demanding than IP telephony although the data volumes will be much greater,’ says Dermot Woodgate of Cara. It can be near-live, like TV streaming to a PC window to monitor, for example, what is happening somewhere else like a parliament, tribunal or court. In security applications, anyone on the network could see the view from any IP-enabled camera on their PC screen – excellent for late night workers in a lonely building. Or a keyholder hearing an alarm could log on remotely and see the views from security cameras. Neil Wisdom has a more interesting idea – how can employers keep their staff at their desks in World Cup time? — streaming TV to the desktop, of course.
Wireless
There seems to be general agreement that wireless networking has joined the mainstream in the last couple of years, not as an alternative to wired networks but as a very useful complement. The commonest use today is for conference rooms and hot desking arrangements for staff who just visit head office from time to time.
IBM’s Anthony Galligan pointed to other situations like temporary projects, mobility around a campus and training. Training was referred to by several consultants. Most organisations have not the space or resources for permanently equipped training rooms. But with wireless networking a class of students and PCs can be set up quickly and easily in any available space.
The most commonly cited examples of situations where wireless is almost the only networking solution are projects (often involving teams in temporary locations), events such as exhibitions and conferences and historic buildings where cabling is either not an option or would involve prohibitively expensive craftsmanship to retrofit.
But other applications mentioned include warehouses and shipping/container yards with relatively long distances for maybe a couple of PCs on a network or where IP-enabled bar code scanners are used or local printers for dockets, labels, and so on. In retailing, wireless EPOS gear allows a lot more flexibility in store layout or numbers of tills – at sale or Christmas rush times as opposed to normal trading, for example.
Security & bandwidth
Security or the weakness of it is a perception that has hindered the acceptance of wireless networking, all experts agree. But Bernard Roche of Hewlett Packard goes a step further and suggests that users who have not set it up properly and then complain are the biggest liability.
‘There are default settings on this equipment that should be changed to secure settings like a unique network name, choice of ‘closed network’, full encryption enabled and so on. But a surprising number of people just leave things alone, which is rather like leaving the default 0000 PIN enabled on your mobile phone! When it is set up properly there is no reason why the wireless end should not be at least as secure as your wired LAN.’
Another issue with wireless is restricted bandwidth: ‘You have a theoretical 11Mbps with 802.11b but with its own protocols and the encryption overhead that will never actually be available for traffic,’ concedes Bernard Roche. ‘And your users are all sharing the remaining bandwidth. Yet the user experience is very good, few complain of speed restriction and our recent experience is that perhaps two out of five network clients who enquire about wireless end up buying it as a component when they have been briefed on what it can contribute.’
‘If your user numbers demand it or there is a contention issue,’ says 3Com’s Ray O’Connor, ‘two access points can be set up to cover the same area with automatic load sharing and balancing of the available bandwidth, all transparent to the users. In any event a new 55Mbps standard is about to be agreed which will really compete with wired networking.’
There is also an 802.11G standard coming along with higher level security. In fact the whole question of standards hangs a bit cloudily over wireless because despite the Wireless Ethernet Compatibility Alliance (WECA) which includes all major vendors, too many standards are purely engineering (IEEE) or industry-agreed and there are no serious promises of backward/forward compatibility or upgradability of equipment.
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