Xrio's Unified Bandwidth Management Blog

For over 15 years video conferencing has been touted as the next thing in business communications. When it was originally launched it was hoped that the technology would reduce business travel and expand international business but the reality has been poor quality video and high cost of installation.

A recent survey of businesses in the USA and Asia found that over 61% of users complained about quality issues with either dropped calls or low picture quality even though the actual video conferencing systems they were using were high quality.

The recent economic downturn has meant that many companies are now looking at ways to save costs and video conferencing systems are now becoming more popular once again.

In order to improve quality of communication many are looking at installing high capacity leased lines which are very expensive when they don’t need to. An alternative is to use low cost Internet bonding solutions which will users to keep costs down and at the same time experience HD video conferencing.

Tags: video conferencing, load balancing, capacity, internet connectivity, dropped calls, survey

A common topic when talking to customers during pre-sales are the differences between load balancing and bonding and which one is best for them.  It's true to say that there is no ideal solution to fit all customers and their requirements.

In order to draw conclusion, we must understand how transmissions are made between 2 hosts, the sender and the receiver.  Are you ready for the science lesson?

What is a connection?

Commonly refered to as a connection or stream, it is a single data transmission that is established through the Internet between 2 hosts.  The TCP/IP protocol contains many types of connection, the most of common of which is TCP.

TCP - Transmission Control Protocol - Establishes a relationship between 2 hosts and provides a reliable connection
UDP - User Datagram Protocol - A fire-and-forget based protocol that offers performance over TCP

Although there are many protocols that make up the TCP/IP protocol suite, most are based on either TCP or UDP.

What is a session?

A session can me made up of multiple transmissions and there are considered two types.  Some applications create multiple transmissions or connections of the same type to improve performance, the most common is HTTP.

When requesting a web site, your computer will open up mutliple connections to the web server, hence you will see multiple image relating to the website, appear at the same time. 

The second defination of a session are protocols such as VoIP and IPSEC VPN's who use multiple, different types of connection for different purposes.  If we take a look at IPSEC, we can see that a UDP connection is first made to establish a security trust between the two hosts or networks, once succeeded a second connection is made to build the encypted tunnel.

How does load balancing help?

When a new connection arrives at the load balancing device, the connection is directed to one of many links using an algorithm specified.  For the entirity of this connection, only the bandwidth of one link can be used.  In some instances this might be desirable, in some it probably won't. When the next connections arrives at the load balancing device, it is directed to another link, thus incresing overall bandwidth and performance of the network.  Moreover, if an application creates multiple connections to the destination server, its possible that in can benefit from increased bandwidth if the load balancing device chooses to route those connections over multiple links.

The drawbacks of load balancing

If a link fails during a transmission

How does bonding help?

Bonding will take each single connection and

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