1.5. Techno-economic aspect of moving from classic telephony to VoIP

1.5. Techno-economic aspect of moving from classic telephony to VoIP
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Many institutions are facing investment decisions with respect to replacing or expanding their existing telephony infrastructure, which currently mainly consists of large PBXes with proprietary phones and interfaces. As is there such a clear trend of replacing old-style (TDM) PBXes by IP telephony ones, it is important that there is a guide on how to attach such an IP telephony solution to the existing network. The existing IP connectivity can be used as the basis for establishing good communication between scientists that might not use traditional, still relatively expensive long distance calls as extensively as they could use IP telephony. In addition, the potential for enhancing IP telephony by additional services that support scientific cooperation makes IP telephony an attractive solution, even where financial constraints are not the driving force.

IP telephony can provide a number of benefits beyond replacing existing PBX/PSTN telephony:

Enhanced speech quality: - The PSTN (and most PBXes) are limited to 3.1 kHz, 8-bit/sample audio. It is likely that future IP phones can provide CD quality, possibly even stereo audio. Even where the additional bandwidth required for this extreme level of quality cannot be provided, modest codecs such as G.722 (7 kHz speech bandwidth) can be used to provide better quality than conventional telephony.
Improved availability: - There are many aspects of availability: Lowering the cost can make telephony more available to low-budget activities. Redundancy can provide as good as (or even better) reliability than traditional telephony. Integrating telephony with location-based computing and group awareness systems can make the communication partners much more "available" - or provide means to transfer communication to a point in time where it is more appropriate than the usual interrupt-driven telephone call.
Improved coverage: - In a similar argument, IP telephony can be made available in places where traditional phones are often not available in a university, e.g., lab settings (in particular, student labs). Also, many universities still consider the cost of phone installations high enough to force their employees to share phones in a common office - again, not necessary when workstation-based IP telephony is used.
Improved mobility: - It is very easy to move an IP phone to another room. There is no need to deal with ports on the PBX and changing dial numbers. Simply plugging it into an ethernet socket in a new room makes it available.
Improved media integration - IP phones can be enabled to add media to an ongoing call as required, e.g., viewing a picture or drawing on a whiteboard. Using workstations themselves as IP phones can facilitate providing this function, while the standards are not yet there for coupling phones and workstations.
New services - As IP telephony evolves, it can be used to provide new services (like user defined call processing) or integrate existing concepts, e.g. Presence, Location Awareness or Instant Messaging. Because of the open standards available for these services they need not to be limited to vendor-specific solutions. In few words, it can be much easier to deal with issues such as CTI (Computer Telephony Integration) paving the way to a completely new way of understanding telephony.
Research - As mentioned before, the protocols and standards used for IP telephony are open and publicly available. This allows research institutions to work on their own services and solutions.

Anyway, it is important to point out that before introducing IP telephony into the organisation network, several issues unknown to the old telephone system has to be taken into account. A rough non-exhaustive list may include addressing (special subnet/VLAN for phones), Quality of Service (QoS), security, gateways positioning, firewalls interfacing and, last but not least, maintenance of the system (backups, spares, etc., something not very common in legacy PBX world).

With regard to the economic aspects, the packetization of voice using Voice over IP has given rise to new international telecommunications carriers. These carriers have distributed network architectures using the Internet as a platform. VoIP networks have an architecture offering the most efficient way to implement multilateral telecommunications agreements, thus eliminating the need for carriers to engage in hundreds of bilateral traffic agreements as is required between traditional circuit-switched PSTN carriers. Moreover, since packet networks are software driven, they can be configured more dynamically than traditional PSTN networks can. For example, with a global voice over packet network, new destinations are available to all users on the network, without the need for additional investment every day.

IP telephony telecommunications companies may expand the availability of services to a wider audience. IP telephony technologies can be used to build out voice networks more rapidly and at a lower cost than legacy PSTN systems. Easier deployment of Voice over IP networks can bring the benefits of telecommunications to more people in a much shorter time frame than would be possible with conventional PSTN networks. At the same time, not having to build extensive infrastructure gives many companies a motivation in migrating to IP telephony architectures.

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