With the explosion of the Internet and the rise of wireless devices, IP address space is a wanted commodity. While there is a need in some parts of the world, Canada and the U.S. aren’t in crisis mode yet, thanks to existing technologies such as network address technology (NAT). Now, an emerging protocol may be poised to improve upon what NAT has already accomplished.
It was a decade ago when NAT was created. It allows for the use of one set of IP addresses to be used for private traffic within an enterprise and a second set for public traffic over the Internet. By doing so, it cuts down on the number of actual IP addresses a company uses, and thus conserves them. NAT is the industry standard but it’s far from perfect. Those that want NAT replaced say it suffers from suspect security and doesn’t work well with virtual private networks or end-to-end encryption.
Enter Realm Specific Internet Protocol (RSIP), an experimental protocol that is being considered as a possible replacement to NAT by the Internet Engineering Task Force (IETF). RSIP offers what NAT does, except that it offers greater transparency to the end user, improves upon security and is said to be able to handle larger, more intense multimedia applications. The IETF has approved RSIP only as an experimental protocol.
The fact that RSIP has not been widely used should comes as no shock, considering how widespread NAT is and the wholesale changes needed to make RSIP work.
“Let’s say you wanted to go ahead and use RSIP. The RSIP server will provide you with an IP address and a range of port numbers that a client can utilize and look at the packets on your machine and modify them for you, (but) there is no RSIP client for Windows,” said Ken Kauffman, product management, Internet technologies division at Cisco Systems in Research Triangle, N.C.
Cisco was one of the founding companies involved in the development of NAT, and continues to be one of its proponents. Aside from not having a client on the PC, Kauffman said that to run RSIP would also require a change in the TCP/IP stack. He did say that RSIP can handle more multimedia types of applications. Kauffman made it clear that Cisco views RSIP as one of many protocols being considered.
“NAT is going to be around for a long time,” he said.
Mike Borella is well-acquainted with RSIP. He tested it on a high-density VoIP platform that allowed multiple calls to be terminated using the same IP address. Borella, the manager of wireless systems and architecture group at CommWorks Corp. in Rolling Meadows, Ill., said the biggest advantage to a RSIP implementation is not having to constantly upgrade the firmware in the gateway router to support new protocols.
“RSIP is a lightweight mechanism that you can put into your NAT gateway with a firmware upgrade and a client mechanism on your PC in the form of a device driver. It doesn’t require a lot of detailed operating system work,” he said. CommWorks, a subsidiary of 3Com Corp., is one of the main proponents of RSIP.
However, with NAT so entrenched within the PC and Internet environments and supported by Microsoft on the operating system side, some believe it is unlikely that RSIP will ever replace NAT.
“If we were to start all over again and our Apple PCs and Windows PCs were RSIP-compliant so that they had RSIP clients in them, that would work fine,” Kauffman said.
To drive the point home even further, one research analyst said network managers in Canada and the U.S. are reluctant to change from a system that is working just fine and that the reasons for moving away from NAT aren’t convincing enough.
“The two big ones, more address space and QoS (Quality of Service) are both mute in North America, (since) address space is still adequate and QoS isn’t being implemented yet anyway,” said Stan Schatt, vice-president and research leader at Giga Information Group in Carlsbad, Calif. Countries like Korea and Japan are mandating a move to [IPv6], but Schatt argued it is not going to be as easy to coax enterprises across Canada or the U.S. into following suite.
Kelly Kanellakis said it is unlikely that RSIP will catch on because all the hosts would have to be changed. “Microsoft basically has to decide that RSIP is a viable thing to do and they would have to start shipping Windows with RSIP-enabled hosts,” said Kanellakis, the director of technology at Enterasys Networks Inc.’s Canadian arm in Mississauga, Ont.
