Networking / Beginners

Business Considerations

Table below documents business issues to consider when selecting a routing protocol.

Important Business Considerations for Routing Protocol Selection
Integrated IS-ISOSPF
Multivendor EnvironmentsYesYes
Proven TechnologyYesYes


Many companies prefer to use protocols that are based on standards whenever possible; this is strongly recommended in every network. Networks running without the protocols and standards will eventually cause problems.

OSPF is a standard protocol that was developed by a committee of the IETF as an alternative to the RIP protocol. OSPF is defined in RFC 2328.

IS-IS is a standard protocol that was developed by the ISO. IS-IS is defined in International Standard 10589. Integrated IS-IS is a standard extension to IS-IS, which was developed by the IETF. Integrated IS-IS is defined in an Internet Draft.

Multivendor Environments

Large networks being designed today do not have the luxury of assuming a single vendor environment. It is common to have portions of a network that are provided by one vendor and other portions that are provided by another. You can use several techniques to permit multivendor environments. The most common technique is to use the same routing protocol on all the routers. To compare the viability of OSPF versus IS-IS for a multivendor environment, consider the following:

  1. Every major routing vendor implements OSPF.
  2. Integrated IS-IS is implemented by most of the major router vendors.

Proven Technology

OSPF has been available for several years from all the major routing vendors and is being deployed in an increasing number of networks ranging from very simple to very complex.

Integrated IS-IS has been available from Cisco for several years and is being deployed in a number of significant networks. OSPF is the routing protocol of choice of almost everyone. IS-IS is the routing protocol of choice for networks that need to support both OSI and IP. Integrated IS-IS is the standard routing protocol for DECnet Phase V networks.

[Previous] [Contents] [Next]