Monday, March 11, 2013

What Makes Low Latency Bandwidth Important

Bandwidth is bandwidth, right? What’s really important is how many bits per second you can squeeze down the line, isn’t it? Or is it?

Lower latency bandwidth solutions are available for your business needs...The speed of your connection is one important specification in a bandwidth solution that will meets the needs of your company. Others include availability, packet loss, jitter and latency. Don’t understate the importance of latency in providing a satisfactory WAN service.

What is latency and isn’t it related to bandwidth? In some cases, yes. Bandwidth increases latency when you don’t have enough for the job. If you have a huge file, say a radiology image, that you need to transfer to another location in 10 minutes and it takes 10 hours, you’ll feel the pain. If your VoIP calls are getting derailed by employee internet browsing, you’ll hear the pain. If your video conferencing breaks up so badly that it is unusable, your employee productivity can really be a source of pain.

Latency is the delay between sender and receiver. If you have all the bandwidth your equipment can possibly use, that delay is a function of how fast the packets can get through the line unimpeded. What slows them down is the speed of light in wire and fiber and any delays introduced by routers, switches and amplifiers along the way.

So, how is it possible to have plenty of bandwidth but too much latency? The perfect example is two-way satellite transmissions. You’ve no doubt noticed that on-location live TV reports seem to have a delay that prevents normal two-way conversations. The anchor and the reporter have to each pause before talking or they’ll talk over each other. That’s latency. Most of it is caused by the simple fact that the geostationary satellite relaying the signal is located about 22,000 miles overhead. Even in a vacuum it takes light and radio waves a millisecond for each 186 miles of distance or a full second for each 186,000 miles. This results in a minimum delay of a quarter-second for a one-way transmission or half a second for a round trip.

Is there a technical way to reduce this latency? Nope. As long as we use electromagnetic waves we’re stuck with Einstein’s speed limit. If you want lower latency, you need to use shorter paths.

One way that carriers are reducing latency is by establishing point to point connections that run in as straight a line as possible. This can mean new fiber installations with minimal length between cities. It also means removing as much electronics from the path as possible. Each box adds a little latency as the signals are converted from light to voltage to light again. Of course, bandwidth has to be high enough that it appears to be transparent to the application.

An extreme example of lower latency requirements is high speed financial trading. It’s computers making trade decisions and placing the orders far faster than a human broker possibly could. Half a second delay is eternity to such systems. Every millisecond counts when you are issuing hundreds or thousands of buy/sell orders every second. Even an optimized fiber optic link from out of state or across national borders may have too much latency. The optimized solution is to move your computers into the same data center as the trading floors. This gets the delay problem from milliseconds down to microseconds and nanoseconds.

You may not need such highly optimized latency reduction solutions for your business. However, you should be aware that cloud services can become latency limited. Any signal delay through your own company LAN is likely unnoticeable. Stretch that connection out a thousand miles or two over the Internet and you may experience noticeable response delays in interacting with your applications. If you can’t live with the performance of the public Internet, you need a latency optimized bandwidth solution.

Big fiber optic carriers like Zayo, MegaPath and XO communications offer high bandwidth low latency private line connections that can improve the performance of your cloud based applications. You’ll also need this for high quality VoIP telephony and video conferencing. Be sure to investigate the impact of latency on your SIP Trunks and multi-location networking through MPLS. Low latency solutions are available for just about every need.

Do you need lower latency as well as higher bandwidth? Get competitive pricing on low latency high speed bandwidth solutions for local, interstate and international connections.

Click to check pricing and features or get support from a Telarus product specialist.

Follow Telexplainer on Twitter