WAN Redundancy is a cornerstone of strategic imperatives that govern Business Continuity decisions. While Business Continuity concerns tend to place a heavy emphasis on the large scale disasters, these occur very rarely but nonetheless need to be taken into account. However, a much more frequent occurrence that affects Business Continuity is WAN downtime. It is estimated that introducing WAN Redundancy to networks eliminates as much as 35% of Business Continuity concerns.
There are many paths to WAN Redundancy. The most basic form is to have a shadow line to be used in case of failure of the primary line. However, while this may save on some initial costs, it is inefficient and requires manual handling. If no technically competent person is on hand, the resulting WAN downtime could be disastrous for a business due to the delay of failover.
Border Gateway Protocol was one of the first automated systems introduced several years ago to deal with routing issues. This system while cumbersome and difficult to program and maintain, provides a measure of WAN Redundancy.
FatPipe WAN Redundancy technology, based on the concept of router clustering, with the added benefit of dynamic load balancing, was introduced around year 2000. This plug and play system allows a greater degree of control of WAN Redundancy.
WAN Redundancy Technology – Router Clustering
The conceptually simple solution to automate WAN Redundancy is based on the principle of multiple Internet connection from multiple ISPs or Telcos being aggregated by one network appliance that sits on the edge of the LAN.
Router clustering technology combines multiple data lines from multiple providers. The technology is agnostic to type of data line or WAN, and also towards the ISP or Telco providing the service. Thus this technology can combine disparate data lines such DSL, ISDN, T1, DS3, E1, Cable Modem, Wireless, etc. In fact, router clustering can handle any type of data line that terminates in a router and has an Ethernet handoff or is Ethernet itself. Since this technology is not dependent on the providers doing anything on their networks, it is very versatile and can be used in a variety of conditions.
A natural extension to this router clustering technology is to extend it to other WAN connectivity types such as VPN, Frame Relay, ATM, IPVPN, Private Point to Point Networks, etc. Thus, router clustering technology gives WAN Redundancy to simple Direct Internet Access (DIA) connectivity and to sophisticated networks such as VPN, Managed Services, Private Networks, and can also combine private and public networks, a well.
The main advantages of Router Clustering Devices are:
- Easy to deploy
- Dynamic load balancing
- Does not need ISP or Telco cooperation
- Works with multiple types of data line and WAN connectivity
- Simple GUI interface
- No command line programming
- No BGP programming
For more information visit the following website:
Border Gateway Protocol (BGP) Programming
BGP is one of the main routing protocols used in the Internet. It utilizes a complex set of routing tables of IP networks which maintain network connectivity among autonomous systems. Rather than using traditional IGP metrics, BGP uses routing decisions based on network policies or rule sets.
BGP’s use of routing protocols makes it a very difficult to deploy technology for WAN Redundancy. The programmable router used to attain WAN Redundancy has to have sufficient memory to hold the ever expanding list of routing tables that are necessary for proper operation. Added to this, BGP programming is very complex and requires people with specialized expertise to set it up. Since most companies do not have BGP experts on staff, outside consultants have to be relied upon and thus increased the expense of deployment.
BGP routing uses a static system to dessimnate information over two Internet connection. These have to be high-end lines, and cannot be used with DSL lines. One can combine different types of line usinging BGP, but only when each provider gives permission for the end user to bond the lines with a competing provider. Many times, ISPs will not cooperate with another ISP.
While BGP does provide for WAN Redundancy, some of the concerns are:
- Implementations needs expert BGP programmers
- Require routers to be upgraded to programmable ones with maximum memory
- Does not do load balancing, but there are ways to use two lines at the same time. There is not intelligent decision being made by the router in terms of how to best utilize the available bandwidth
- Can “weight” traffic, but there is not dynamic load balancing.
- Needs ISP and Telco cooperation
- Needs programmer at site and also provider sites
- Changes to the network need more programming
For more information please read:
- LinkRank A tool for BGP routing visualization by University of California, Los Angeles
- BGP Routing Resources (includes a dedicated section on BGP & ISP Core Security)
- BGP table statistics
- ASNumber Firefox Extension showing the AS number and additional information of the website currently open
- RIPE Routing Information Service collecting over 550 IPv4 and IPv6 BGP feeds at 14 sites around the world
- RIS Looking Glass into the Default Free Routing zone of the Internet
- RISwhois providing IPv4/IPv6 Address to BGP AS Origin Mapping
- RIS BGPlay BGP routing visualization tool by Università degli Studi Roma Tre
- Linux Magazine: Demystifying BGP (Good, Detailed BGP explanation; requires registration)
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