What is Latency? - How to reduce Latency?

What is Latency?

Now a Days, Latency is a command word for all the users as whoever using internet. We only know about the good things related to the high speed of internet.

In terms of Network latency means the network packet will take some times with request to travel from sender to receiver and from receiver to process the request. But in terms of simple words The Round trip time from one browser to the servers. 

Network latency is used to indicate any kind of delay that happens in data communication over a network. Network connections in which small delays occur are called low-latency networks whereas network connections which suffers from long delays are called high-latency networks.

High latency creates bottlenecks in any network communication. It prevents the data from taking full advantage of the network pipe and effectively decreases the communication bandwidth. The impact of latency on network bandwidth can be temporary or persistent based on the source of the delays.

Possible Causes of Network Latency:

• Anti-virus and similar security processes by often requiring complete message reassembly and tear down before sending on.
• Problems through the transmission medium as such as a WAN or fiber cable has some limitations. 
• Errors with the router or switches as each gateway takes time to examine and change the packet header. 
• Storage delays when packets are subject to storage or disk access delays at intermediate devices like switches and bridges. 
• Software malfunctions at the user level can cause some delays from a user perspective. 
• The propagation time takes a lot time for a packet to physically travel from its source to a destination.

Network latency can be tested through ping tests and trace routes. Most of the time, a packet's round-trip time is measured. With the help of this analysis, network administrators can re-route packets to minimize the network latency.

Types of Latency:

• Fiber Optic latency 
• Audio Latency

How to reduce Latency?

Latency can be reduced by following below things. Reducing an amount of server latency will help with a load your web resources faster, with improving the overall page load time for visitors.

• HTTP/2:   The use of the ever prevalent HTTP/2 is another great way to help minimize latency. HTTP/2 helps reduce server latency by minimizing the number of round trips from the sender to the receiver and with parallelized transfers.
  
  
• Fewer external HTTP requests:
  
  Reducing the number of HTTP requests not only applies to images but also for other external resources such as CSS or JS files. If you are referencing information from a server other than your own, you are making an external HTTP request which can greatly increase website latency based on the speed and quality of the third party server.
  
  
• Using prefetching methods:
  Pre-fetching web resources doesn’t necessarily reduce the amount of latency per se however it improves your website’s perceived performance. With pre-fetching implemented, latency intensive processes take place in the background when the user is browser a particular page. Therefore, when they click on a subsequent page, jobs such as DNS lookups have already taken place, thus loading the page faster.
  
  
• Using a CDN:
   
  
  Using a CDN helps bring resources closer to the user by caching them in multiple locations around the world. Once those resources are cached, a user’s request only needs to travel to the closest Point of Presence to retrieve that data instead of going back to the origin server each time.
  
•  Browser caching: Another type of caching that can be used to reduce latency is browser caching. Browsers will cache certain resources of a website locally in order to help improve latency times and decrease the number of requests back to the server. Read more about browsing caching and the various directives that exist in our Cache Control article.

What is the solution?

If you are a home user then there are no good solutions to it as the Internet Service Providers do not guarantee a minimum or average Latency for a normal user, most of the apps do take this into account that there may be a variable latency on the network and you have to depend on it.