Michael.Dillon@btradianz.com wrote:
Right, cause phone number portability is up and running for several
sets
of prefixes in various regions across the world[1], so there's definitely nothing we can learn from them. ;)
Well, we can learn from them that circuit switched networks are different than packet switched networks. Beyond that not much.
I disagree. There are many parallels and in many ways the telephony operators are struggling with the same kinds of problems that we are. NANPA has forecast that the North American number plan will be exhausted within 20 years. Just like the IPv4 address space.
Their plan is to extend the number plan by two digits using 4-digit area codes and 4 digit central office codes. Rather like IPv6's extended address length. The new digits will be introduced at the same time so that everyone will dial an extra digit at the end of their existing area code, and another extra digit at the beginning of their central office code. Today you would dial (703)227-0660 to reach ARIN's help desk. After the change you would dial (7030)0227-0660. Full details here: http://www.atis.org/inc/docs/finaldocs/020107029.doc
NANPA's website points to more information. http://www.nanpa.com/index.html
There is also a North American Numbering Council that meets regularly and has several working groups. http://www.nanc-chair.org/docs/documents.html
It is foolish to regard people outside the IP networking industry as inferior. Good ideas can come from anywhere and we can often understand our own area of interest much better by comparing and contrasting with other similar areas of interest.
There is a major difference between phone numbers and IP addresses which makes direct comparisons harder. Phone numbers are more like Domain names (+email addresses behind them) than IP addresses. People use phone numbers the same way they use domain names. They remember them and use them to access other people, or companies. I haven't seen many billboards with IP addresses on them lately. Nobody cares about the actual IP address. Only the computer does at the time of the DNS lookup. So an IP address is only used as underlying transport vehicle of data. For the enduser it doesn't have any direct significance. A phone number has significance to the end user and has a hybrid function as underlying routing element to varying degrees too. The entire problemset with IP address portability comes from two issues: Ease of ISP changes and redundant connectivity. The former could theoretically be solved with with better procedures and methods for host address assignment. However it still requires some labor intensive transition period and the IP addresses are much tangled with other things like DNS and so on. The second issue is IP architecture specific. The PSTN, due to its symmetric nature, doesn't have the redundancy problem to the same extent as the Internet. For the IP prefix however you have to participate in the global routing system to survive link losses. Without any shim6 or SCTP stuff that is. Again, phone numbers and their portability can and should not be compared with the IP address portability issues. They're very different animals. -- Andre