Border Gateway Protocol (BGP) is the Internet routing protocol. It is a path vector protocol, which selects the route based on static metrics (AS path length, local preference). The problem is that none of these metrics reflect the actual performance or cost of the path. Whether a route is short or long distance, BGP is not able to make any difference. Whether a path is properly forwarding packets or dropping some of them, again this protocol fails in detecting such quality problems. This paradigm results in the inability to detect failures and poor performance:
- Long paths
Large delays cause frustration to web users. On business-to-consumer applications this directly affects the actual sales conversion rates. It severely impacts the perceived quality of voice communication and leads users to shorten voice calls. It also results in very noticeable performance problems with gaming applications.
- Packet loss
High packet loss rates usually produce the same experience as high delays. However, packet loss turns into a bigger issue with video applications such as streaming and video conferencing.
- Broken links
Routing equipment sometimes undergoes inconsistencies in the routing and control planes. In this situation, the BGP mechanism sees the network as properly functioning while the interfaces and routing process are actually not forwarding packets. In this case, the users cannot access their applications anymore until a manual action is executed on the equipment to restore the function of the network. Similar situations are also seen when operators implement wrong access-lists or flood protection mechanisms actually block legitimate user traffic.
Detecting failures and measuring Internet performance requires application traffic to flow back and forth to remote peers and from remote users. Our software executes thousands of tests per minute, to create a full description of the customer network connectivity, and notices all changes almost instantaneously. Once properly configured via the GUI, the automated probing does not require any manual intervention.