by Rikus Jansen, Head of Voice & Unified Communications at EOH

A successful unified communications (UC) system in an enterprise environment requires a solid network infrastructure. UC includes an array of communications and multimedia tools, like presence information, IP telephony, rich media, video-conferencing, instant messaging, email and collaboration. These place requirements on the network in terms of speed, bandwidth and reliability.

Proper network design is required

Because of the different types of applications that run in a unified communications environment, it places strict requirements on IP packet loss, packet delay and delay variation (jitter).

All layers of the UC system architecture, including call routing, call control, applications and services, and operations and serviceability rely heavily on the ability of the network to support their services. To achieve proper design of the network infrastructure, a robust and redundant network must be built from the ground up. By structuring the LAN as a layered model (access, distribution and core layers) and developing the LAN infrastructure one step of the model at a time, a highly available, fault tolerant and redundant network can be built.

Proper WAN infrastructure design is also extremely important for normal IP telephony operation on a converged network. Wireless LAN infrastructure design becomes important when IP telephony is added to the wireless LAN (WLAN) parts of a converged network.

The imperatives of unified communications

Once the network infrastructure has been properly designed and implemented, you can successfully add network and application services across the network, which provides a highly available foundation on which unified communications can run.

The ability to scale the network infrastructure so that it is capable of handling UC applications and services requires providing adequate available bandwidth and the capability to handle the additional traffic load created by the applications.

The type and number of endpoints are an important part of the net load that the system must support. There are different types of endpoints and each type imposes a different load on the unified CM. Next to this, the quantity and quality of call traffic also places a large requirement on the unified CM. When considering call traffic other complexities arise from calls between endpoints that work on different protocols, such as between SIP and SSCP-based phones, if calls are transferred and if conferencing is required.

It can be challenging to determine the network requirements of a large unified communications system comprising a number of separate applications working together. However, an understanding of the functional requirements of the software and the performance capabilities of the hardware platforms certified for running the software can be very helpful in making an accurate estimation.


Rikus Jansen Rikus Jansen is a Unified Communications specialist. Rikus entered the South African technology space in the late 1980’s as one of the pioneers of 3D animation and video effects in the broadcasting industry. This gave birth to his career in the corporate ICT outsource space. In 1997 Rikus became the managing director and co-founded of Ensync Voice Solutions, a unified communications company. After the merger of the Ensync companies into the JSE listed ICT Company EOH in 2010 he now heads up the EOH Voice and Unified Communications business, which is one of the leading communication providers in South Africa.