tuples that indicate the list of destinations that can be reached by a BGP speaker. The update message also contains the path attributes.
In the event that a route becomes unreachable, a BGP speaker lets the other speakers know there is a problem by removing the invalid route. Once this happens, the routes that were unreachable then become unavailable for use.
The BGP protocol also offers Keepalive messages which allow one speaker to poll another speaker to ensure a connection is still alive. By doing this, the speaker can determine reachable and unreachable paths before traffic flows through the network. This, in turn, speeds the overall movement between switch or router architectures.
Clearly, BGP-4 promises to provide a new routing structure for today's design community. But, for this to happen, BGP-4 must gain mass acceptance in a variety of system architectures. The challenge is that BGP-4 software is not easy to develop. To make it work properly, designers must have a detailed understanding of not only where traffic must end up, but also on what it will take to get the traffic there. With so many route options and paths available, this is truly a difficult task.
That's where the OPTIRoute BGP-4 package steps in. Designed to run on a combination of host processors, network processors, custom-developed ASICs, or other processing engines, this software module provides a path vector routing engine that is fully compliant with RFC 1771, BGP-4, and related specifications. Through this software package, designers can implement a routing solution that can support more than 1 million routes. In fact, according to NetPlane, this new software solution will support more than 2 million routes over the next six months.
One of the key benefits of the software module is its ability to propagate externally learned routes through an interior gateway protocol (IGP), such as OSPF, complete with policy interaction, which is a key challenge in BGP-4 implementations. To make this happen, the software package is broken into two variants - interior BGP and exterior BGP. The internal BGP, in accordance with configured policies, provides externally learned routes with paths attributed to other external BGP routers within an autonomous system. The external BGP then handles the inter-AS routing.
The external BGP and OSPF protocols should be visualized on different levels. These levels usually meet at a common point where a router is configured as both an OSPF area border router (ABR) and a BGP external peer. Linking the OSPF and BGP levels is not an easy task. By splitting the BGP protocol into two variants, the software module solves this concern and eases the implementation of BGP-4 in switch and router architectures.
The BGP-4 software module is part of the OPTIRoute portable Internet protocol routing solution, which includes an OSPF module, a policy management mechanism, simple network management protocol (SNMP) support, a forwarding information database (FIB), and a control line interface (CLI). Integration is also provided to an MPLS software package from the company. In addition, this routing solution provides interfaces to external components, such as TCP/IP stacks, redundancy, and distributed messaging.
Application programming interfaces (APIs) have been included in the BGP-4 package so that designers can easily access other OPTIRoute modules, such as OSPF and MPLS. This allows designers to set up a distributed routing scheme that works across a number of network interface cards (NICs) see Figure 1. For example, a designer may want to implement BGP-4, MPLS, and OSPF functionality all in the same system architecture. Through the open APIs, designers can allow each of these software packages to sit on their own cards and be managed through a multiprocessing scheme.
In addition to providing an open interface to other OPTIRoute modules, the open APIs also allow the BGP-4 software package to work with a host of router platforms. Traditionally, BGP-4 implementations have been hardware dependent, varying from platform to platform, even within a company. By offering these open APIs, the new BGP module can be easily integrated into a variety of switch and router system platforms from a variety of developers.
Making virtual routing a reality
Virtual routing is another key feature provided by the OPTIRoute software solution. As workforces become more remote and virtual private networks (VPNs) become more popular, there will be a growing need to support virtual routes in a system architecture.
Through the BGP-4 package, a completely separate network can be assembled to handle an individual customer. This allows for complete segregation of network address spaces for each customer represented by a virtual route. Thus, designers can build equipment that allows service providers to offer IP- based VPN solutions to small and medium sized business that do not have the resources, or the desire, to implement their own network between multiple locations.
The BGP-4 software package is written in and provided in C language. It is processor and OS independent.
The OPTIRoute BGP-4 module is available immediately. Initial pricing for the entire OPTIRoute product family begins at $250,000. Pricing on the BGP-4 module will start at $150,000. For more information on the product, contact NetPlane Systems, 888 Washington Street, Dedham, MA 02026. Phone: 781.329.3200; Fax: 781.329.4148; URL: http://www.netplane.com.
Robert Keenan is the Editor-in-Chief of Communication Systems Design. When not finding routes in the Internet world, he can be reached at firstname.lastname@example.org.
- Halabi, S., Internet Routing Architectures, Second Edition. Cisco Press, Indianapolis, IN, Copyright 2000.