Fine-Tuning Your SIP Infrastructure

November, 2013

Sytel has considerable experience in configuring SIP services for a range of markets. Based on this, here are 3 potential issues that can seriously degrade the quality of your service.
Over the next three months we will be looking at SIP infrastructure and configuration – one of the major causes of headache for IT managers working with new IP contact center installations.

Sytel has considerable experience in setting up and configuring SIP services for a range of markets, from global market research to cloud contact center service providers. Here, we look at three major challenges faced in maintaining high voice quality, and offer solutions based on this experience.

1 –  The challenge of voice break-up

Back in the days of analog phones with T1/E1 lines to the network, there was no complication; no configuration was needed and the network manager could sleep at night.

With SIP, every service you are trying to use – voice, ad hoc video, data up/download, etc – is contending for bandwidth. This can lead to poor voice quality and unacceptable breakup, as voice fights for enough resource.


The only way to achieve consistently high quality voice is to prioritise voice over other traffic. For that you must use managed switching throughout the network, and also make sure your network backbone has enough capacity to deal with total load.

Read more

2 –  The challenge of voice delay

In the world of SIP, as we know, voice sessions are split up into many packets. When these are sent over the wire, two things happen:

  1. At each leg of the journey, packets are held in a queue until they can be ordered properly. But a journey can contain many legs, and at each one, delay (or latency) is increased.
  2. In the interests of efficiency, each leg of the journey may use one of several compression protocols. But each time any translation is required from one to another, a delay is introduced. Again, over the course of a journey, these add up.


To minimize latency, firstly minimize the number of legs in a journey by certifying your SIP telephony stack directly with your carrier. Secondly, use  session border policies to minimize the compression/ decompression events within a journey.

Read more

3 –  The challenge of virtualization management

Virtual Machines (VMs) are great – great for saving money on hardware, great for compartmentalizing processes. Trouble is that, unlike dedicated hardware, VMs will be contending for memory & CPU resources. As SIP and RTP processing is resource-intensive, a strict policy to dedicate resources is essential. The temptation is that when times get tough, and other VMs require extra resources, these are taken from the contact center allocation.


Don’t do it! Do not change or reallocate under any circumstances. Things can get messed up very quickly. The easiest way to manage this is to ensure the contact center infrastructure has its own set of dedicated VM hosts.

Read more

In our next blogs, we will expand on these topics, focusing on what you can do to meet these challenges and ensure you have a great SIP service.

What We Offer

Sytel Limited develops and supplies Softdial Contact Center® (SCC), offering multimedia, multichannel, fully blended cloud contact center solutions, for quick and easy deployment by partners offering CCaaS or enterprise users. All Sytel cloud components are secure, resilient and scale seamlessly from 10 agents to 10,000+, whether local, mobile or remote.

  • Flexible Contact Center Platform

    Softdial Contact Center™ – tightly integrated modules, designed to deliver at scale

  • Blended Media Desktop

    Fully customisable, multi-channel, multi-session workspace

  • Work Anywhere

    Browser-based tools, no software installation required

  • Cloud Or On-Premise, Multi-Tenant

    Scalable, resilient, secure, proven

  • Customise, Localise, White Label

    Design all user interfaces to individual requirements

  • Integration Via APIs

    ‘Swap out’ components and integrate with 3rd party apps

  • World Class Development

    Continuous evolution pushing technical boundaries


Softdial Contact Center™ (SCC) is designed to be flexible, extensible and scalable, integrating with any legacy equipment, and meeting the most complex of requirements.

  • All Media Types

    Voice, chat, email, social, etc – fully integrated and blended

  • Agent Multi-Tasking

    Work with multiple live contact sessions of any media type

  • Dynamic Media Blending

    Automated, ‘best available’ decisions to blend and balance work load across all media types

  • Predictive Dialing

    Best-of-breed performance under compliance

  • Intelligent Routing

    Smart rules and ‘best-available’ decisions to drive great customer service

  • Agent Scripts

    Help agents achieve and maintain excellence

  • Voice and Screen Recording

    See and hear exactly how agents are interacting

  • Analytics and Data Feeds

    Measure and evaluate performance at every level

  • IVR, Bots & Conversational AI

    Design effective automated flows or integrate with 3rd party providers

  • Customer Journey Tracking

    Stored customer contact history, to aid routing and add context to conversations


A complete suite of tools, with unique flexibility to extend and swap out modules to deliver a tailored contact center solution for any environment

  • Softdial One™

    Highly flexible unified web UI for agents, supervisors and administrators

  • Softdial Scripter™

    Create complex process flow scripts for agents, IVR, chatbots and other applications

  • Sytel AI Dialer™

    Best-of-breed predictive dialing under any compliance rules

  • Softdial Pathfinder™

    Precise routing rules for ‘best available’ connection

  • Softdial Media Server™

    Core telephony functions to manage all inbound/ outbound SIP calls

  • Softdial Reporter™ 5

    Fully customisable performance stats, charts and reports, across all channels

  • Softdial Publisher™

    Comprehensive data output to build your own reports

  • Softdial Recording Monitor™

    Audio and screen recording of agent activity to ensure the highest standards

  • Softdial Campaign Manager™

    Comprehensive configuration and control for outbound campaigns

  • Softdial Repository™

    Central storage and configuration of common resources

  • Sytel Global Compliance™

    Flexible ‘no contact’ rules to protect contact center and consumer


Performance and efficiency for a wide range of business applications

  • Customer Service

    Connect quickly to well equipped agents

  • Sales & Telemarketing

    Maximise agent productivity with best-of-breed predictive dialing

  • Healthcare

    Secure, highly-configurable multichannel communications for excellence in patient care

  • Market Research

    Best-of-breed predictive dialing with CATI integration

  • Collections

    Automated inbound/ outbound blending integrated with any debt management app