How to Multihome Your Internet Lines
Multihoming, i.e. the ability to bring together various Internet connections to create a fatter pipe is a valuable proposition to achieve Internet reliability and optimal performance. There can be multiple ways of multihoming ISPs, but let me start by how not to multihome:
A legacy way of adding multihoming to a network is by making use of BGP (Border Gateway Protocol). BGP was originally designed to replace EGP (Exterior Gateway Protocol) to accomplish fully decentralized routing. However it has found some use in multihoming applications between multiple access links of a single ISP or multiple ISPs. Unfortunately, BGP can have slow reaction time, can be inefficient in terms of performance and can be very cumbersome to set up and maintain since BGP requires you to have access to AS (Autonomous Systems). Despite its shortcomings, BGP was still used to multihome, simply because there were no other alternatives.
The invention of Broadband Bonding / WAN Virtualization (or WAN Virtualisation if you are British), has simplified the multihoming technology to a level where now an organization can simply purchase a Broadband Bonding appliance and plug in any ISP links to achieve perfect multihoming. Not only is it orders of magnitude simpler than BGP to set up and maintain, but it also performs better. Broadband Bonding works similar to the VPN (Virtual Private Network) technology where it sits on top of the transport as a virtual overlay network, in the bonding case, over various ISP links. This allows the bonding to occur at a layer higher than layer 1, layer 2 or layer 3, and therefore can be accomplished without any telco involvement.
What this means is that you can create your very own bonded ADSL, or bonded cable and DSL or bonded DSL and MPLS WAN network by utilizing Broadband Bonding appliances. DSL bonding is the new paradigm shift in Internet load balancers, as load balancing firewalls are being replaced by Internet bonding routers with firewall, QoS and traffic shaping capabilities.
The primary use cases of broadband bonding devices start with Internet reliability, i.e. MPLS failover, T1 failover, etc. The multi-wan router aggregates MPLS together with several DSL lines and provides higher bandwidth and real-time failover capability for the WAN, whereby any outage of the ISP links is shielded from the applications. MPLS traffic can be funneled over the bonded DSL lines in case of MPLS blackout, without disrupting the application – wow!
Is this technology pushing enterprises to look at bonded broadband as an MPLS alternative? Since this new breed of load-balancing routers have the capability of bonding, Internet traffic shaping, traffic grooming and real-time adaptation with layer7 control, applications such as VoIP (real-time applications), Citrix (chatty applications) and any other Internet traffic can be intelligently managed and provided QoS controls that achieve maximized performance for the end user.
Cahit Akin, CEO, Mushroom Networks, Inc.
Mushroom Networks is the provider of SD-WAN (Software Defined WAN) and NFV solutions capable of Broadband Bonding that enables self-healing WAN networks that route around network problems such as latency, jitter and packet loss.