Address "portability"

Matthew Kaufman matthew at
Fri Apr 5 22:57:18 UTC 1996

Original message <199604052143.NAA28351 at>
From: scharf at (Jerry Scharf)
Date: Apr  5, 13:43
Subject: Re: Address "portability"
> >  > 
> >  > Portable addresses is an illusion, as it does no scale. 
> >  > 
> >  > Give me a call when you convinced the phone_company to make my phone number 
> >  > work in
> >  > California. 
> >  > 
> >  > --Peter
> >  >-- End of excerpt from Peter Lothberg
> >
> >
> >  The California PUC has approved local phone competition within California,
> >  with the requirement the phone number portability (between carriers) be
> >  fully implemented as soon as possible. Making your phone number stay the
> >  same no matter whether you're a PacBell or MFS or TCI customer is exactly
> >  the same problem as making IP addresses portable... just wait until ISPs
> >  are regulated, and they get the same mandate.
> >
> >  -matthew kaufman
> >   matthew at
> >
> Not quite. If I move today from San Francisco to San Jose, I have to renumber
> because of area codes. This provides first level hierarchy, which the Internet
> doesn't have (actually second, country codes are the first). The phone
> companies also have settlements worked out, such that a cutout costs the
> group getting the cutout, not the group who has the base or the IXC. Phone
> routing are vastly more restrictive than IP routing.
> Jerry
>-- End of excerpt from Jerry Scharf

1. If everyone in area code 213 (for instance) decided to exercise number
 portability and move their existing number to a new provider, that'd be
 about 3.7 million "host routes" with NO possibility of aggregation.
 That's far more routes than are in my border routers (by about 100X)
 (Presumably CAPs in LATAs with lots of area codes are going to want to
 hold internal routes for ALL of the local area codes, so they can do
 complete bypass... in the Los Angeles area that'd at least quadruple this
 routing table requirement)

2. The costs of portability in the latest proposals I've read are to be
 shared between the existing and the new providers, with the visible end-user
 cost of "keeping your number" relatively low

3. It may be technically stupid, but it is what consumers want, and the PUC
 and FCC are on their side. I still won't be surprised when the "number 
 portability" precedent gets picked up by a regulatory agency and forced on 
 the Internet, at least within the United States.

-matthew kaufman
 matthew at

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