Link Management

Overview

Our Link Management solution is one of the best examples of how existing Free Software tools and simple techniques can be combined to solve important problems and offer tremendous value-add to customers. Outlined below are the fundamental concepts and technical details of this solution.

Problems with conventional Internet access

The most common and conventional way to connect to the Internet is to have a single connection to the Internet. The connection could be a high bandwidth leased line or a ADSL connection.

The problem with such a setup is that it could be limited to one ISP or there might be technical limits on how fast the connection can be. In either case the connection (and the ISP) becomes a single point of failure for the organisation's Internet access. Having a single connection from a single ISP means that failure of this connection will cut the organisation off from the Internet completely.

Absolute technical limits on the type of connectivity mean that after a certain limit it is not possible to grow Internet speeds or the bandwidth available to users in your network.

Multiple Connections to the Internet

Having multiple connections to the Internet takes care of both of these issues. Multiple connections ensure that failure of one link (or ISP) does not cause complete disconnection from the Internet. It also enables one to greatly increase the total bandwidth available.

Aggegating Bandwidth and Distributing Load

Aggregating the bandwidth of multiple Internet connections allows you to provide faster Internet access. The individual bandwidth of the various Internet links available gets aggregated to give users a much faster Internet experience.

The way bandwidth aggregation works is by distributing the Internet requests from users in a round-robin fashion to the Internet links available. This ensures that, on an average, requests are evenly distributed among the available Internet links.

Further follow-up traffic to that Internet request will then be transacted on the same link. This implies that while a single individual download will still be limited to maximum bandwidth constraints of a single Internet link, multiple users will now be able to do such downloads at the same time without eating into each other's bandwidth usage.

This round-robin load distribution can also be weighted in favour of a particular link - especially in cases where there is a difference in the respective capacities of the individual links. This will send traffic in the specified ratio.

Handling Failure

While its good to have multiple links and aggregate their bandwith, its equally important to detect and handle link failure. A failed link has to be dropped from bandwidth aggregation policies so that traffic does not get routed over it.

All links that are part of a bandwidth aggregation group are actively monitored to detect their availability and failed links are immediately removed from the bandwidth aggregation group. Failed links are also consistently monitored and as soon as a link become available again it is added to the link aggregation group.

Deliverables

How do we help you?

We help you build and integrate this solution through the following steps:

  • We help you in understanding your bandwidth requirements

    Our work on this solution really begins with understanding - not software installation. It is very important for us to understand your bandwidth requirements, how you are going to be using the bandwidth and what advantage that you want to draw from aggregating bandwidth. Your nature of work also has an influence on the configuration of your Link Management solution.
  • We deploy and integrate the solution for you

    The next step is to install the deepOfix OS and integrate the links into the server. We then test to ensure that each link is individually working and functional. Configuring link aggregation and load distribution takes care of enabling Internet access immediately. Any traffic from the LAN now gets routed over multiple links!
  • Finally, we enable and configure links failure detection and failover
    This is critical because a link can stop responding momentarily for some reason and unless the failure is detected and handled gracefully traffic routed over that link will reach nowhere resulting in loss of Internet access to users on the local network.

We help you validate the benefits of the solution

This is where you actually get to see the complete solution in operation and we try to ensure its water tight enough to take care of all your requirements.

Requirements for the solution

  • Internet links that terminate into Ethernet connections
  • A mid-range server hardware (multi-core CPU, 2 GB RAM, 2x 120GB+ disk drive)
  • 1 network interface for each link + 1 network interface for the LAN
  • A deepOfix server OS

 

FAQ

While, theoritically, there is no absolute upper limit to this, we have had good success with up to four links at present.

This is not required. If the links are not of the same speed or bandwidth, we can tweak the the load distribution configuration to distribute load in whatever ratio it is required.

Will my downloads be faster?

If you test this out using a simple software tool to do just one download at one time, then your results might not be very different from when you were using a single link. The correct way to validate this is to start multiple parallel downloads from multiple websites and check the total Internet speed that you are able to sink. This is because once you start a download from a website on a specific link, all traffic that is a part of that download will be downloaded fomr the same link.