Noction Intelligent Routing Platform is designed to improve the performance and reduce operational costs of a multi-homed BGP network. By adding intelligence to internet routing decisions, Noction IRP leverages a company’s existing internet connectivity to deliver substantial network performance improvements.
Intelligent Routing Platform
Noction IRP actively probes remote prefixes for metrics such as packet loss, latency, throughput, historical reliability and maximum peer capacity. Based on these actively gathered metrics, the platform computes a performance and/or a cost-based route optimization. The platform then announces the improved route to the network`s edge routers via a typical BGP session.
Engineers cannot run thousands of probes per hour in order to determine better traffic paths and analyze historical performance to make routing decisions. By automating the BGP management process Noction IRP reduces the need for engineering effort and eliminates the risk of human error.
Noction IRP operates at the network edge and does non-intrusive traffic analysis in order to detect network congestion and outages. The affected network routes are probed for a set of specific metrics through all the available providers. Based on these measurements IRP automatically reroutes traffic through the best performing path.
BGP routes traffic through the shortest AS-path without taking into consideration critical network performance indicators such as latency and packet loss. IRP is able to measure these metrics and select a better performing transit provider for the traffic to flow through. As a result IRP reduces latency by an average of 24% and packet loss by an average of 89% for the problematic routes detected.
IRP is a complete network monitoring and troubleshooting solution that makes it easy to quickly detect, diagnose, and resolve performance issues. It delivers real-time BGP monitoring that allows visually tracking network performance, generating triggers and sending various alerts and notifications when specific problems occur. The platform is a perfect tool for network planning, delivering Quality of Services, and ensuring the network is performing on its premises.
IRP adds the ability to generate massive cost savings by intelligently balancing traffic among the connected ISPs. Noction IRP incorporates precedence structures into its policy models, in order to adjust and keep predefined bandwidth commit rate levels for each provider link. This leads to lower 95th percentile billing rates and increased headroom in the overall network.
BGP – the protocol that runs the Internet
Border Gateway Protocol (BGP) is a distance-vector routing protocol that is used on the Internet and allows information sent from one Internet point to another to find the right path and reach the recipient.
When it comes to BGP, the first thing to explain is the concept of an Autonomous System (AS). An Autonomous System is a collection of routing points and the connection between them, united by a common interaction policy, which allows this system to exchange data with the nodes that are outside of the system.
An Autonomous System is characterized by a 16-bit or 32-bit Autonomous System Number (ASN) and a pool of IP addresses. Both are issued by IANA (Internet Assigned Numbers Authority), which in its turn delegates control over the distribution of ASNs and other Internet resources to regional registrars.
The connectivity of Autonomous Systems is achieved through static or dynamic routing.
Static routing is quite simple and requires an engineer to manually set the route to the nearest neighbor. In practice, however, connecting even 10 routers to each other becomes a real challenge.
Therefore, dynamic routing was invented for large networks, where devices automatically share information about the available routes with each other and adjust to any topology changes.
Dynamic routing protocols are classified according to the two main characteristics:
1) The way the protocol works in relation to the Autonomous Systems:
- IGP (Interior Gateway Protocol) – working inside the Autonomous System. These include: RIP, OSPF, EIGRP, IS-IS
- EGP (Exterior Gateway Protocol) – working outside of the Autonomous Systems and ensure their connectivity. This includes BGP
2) The protocol’s operation algorithm:
- Distance-Vector – knows the routes only to the nearest neighbors and exchanges a routing table with them. (RIP, EIGRP)
- Link State – knows the entire topology of the network and exchanges the topology table with its neighbors (OSPF, IS-IS)
Clearly, BGP can not be a Link State protocol. Just imagine how many Autonomous Systems are out there on the Internet! Any router will simply fail if it receives this great amount of information.
Thus, BGP is a distance vector exterior gateway protocol that connects Autonomous Systems. A simplified scheme looks something like this:
Since BGP is entrusted with the task of connecting Autonomous Systems throughout the Internet, it must be very reliable. Nevertheless, the protocol does not have a reliable transport method. Instead it leverages TCPs reliability to ensure that the messages and updates are received. At the very beginning, the BGP router initiates the establishment of a TCP session on port 179 to its neighbor. The standard exchange of SYN and ACK takes place.
BGP connections must be carefully coordinated by the administrators of the Autonomous Systems willing to connect. If, for instance, the administrator of AS20 has initiated the BGP process on BR2 (Border Router), specifying BR1 and its ASN as a neighbor, but the AS30 administrator has not done anything, the TCP session will not be established and the systems will remain disconnected. Moreover, the following conditions must be met:
- port 179 is not blocked by the ACL (Access Control List)
- routers can ping each other
- the ASN of the distant Autonomous System was specified correctly
- RouterIDs do not match
If the TCP session is established successfully, the BGP routers start exchanging OPEN messages, in which they report their ASN, RouterID and Hold time. Hold timer is the time during which the TCP session will be supported. In case the conditions listed above are not met, for example, the information about the AS number does not match, then the router receiving the incorrect ASN will notify its neighbor by sending a NOTIFICATION message and will end the TCP session.
If all the conditions are met, the routers start sending each other KEEPALIVE messages with a certain interval, meaning they confirm the parameters accepted in OPEN and sending the notification “I’m still alive”.
Finally, the routers can begin to exchange routing information using the UPDATE message.
The structure of this message consists of the following parts:
- Unfeasible routes length indicates the length of the Withdrawn Routes field
- Withdrawn routes contains IP address prefixes for the routes being withdrawn
- Total path attribute length indicates the length of the path attributes field
- Path attributes contains the properties of the routes: the path origin, preference for the route, the multi-exit discriminator (MED), as well as the information about confederations, communities, aggregation, and route reflection.
- NRLI (Network Layer Reachability Information) contains the information about the networks which are to be added into the routing table – the IP address of the network and its mask.
The UPDATE message is transmitted each time one of the routers receives information about the new networks, while the KEEPALIVE message throughout the entire TCP session.
NOTIFICATION Message is sent when an error is detected. The BGP connection closes immediately after the message is sent. Such message includes error code, its subcode, and also data related to the error.
BGP is most certainly the most complex IP routing protocol currently deployed in the internet. The information above is aimed to provide only the basic understanding of how the protocol works. For more in depth information please consult our Blog or the Resource Center guides.