Hi, Christopher,
Please find my response interspersed.
On Wed, Nov 18, 2009 at 11:36 PM, Christopher Morrow <
[email protected]> wrote:
> On Wed, Nov 18, 2009 at 6:02 AM, Dae Young KIM <[email protected]> wrote:
> > On Wed, Nov 18, 2009 at 3:40 PM, Christopher Morrow
> > <[email protected]> wrote:
> >>
> >> From your txt:
> >>
> >> A. Fundamentals:
> >> o Skeletons:
> >> o ID is global, Locator is local(private) to AS.
> >>
> >> isn't that backwards? ID == my local machine, 'locator' is my network
> >> attachment (or the network that I'm attached to).
> >>
> >> So the ID is required (and unique) only within my network, the
> >> 'locator' is unique globally.
> >>
> >> -chris
> >
> > There are two aspects to this.
> >
> > 1. Having locators local is a necessary first step to avoid the
> gateway
> > (aka IDR(Inter-domain Routing) router) table explosion. By not having to
> > manage global locators, gateways don't have to exchange (locator) network
> > prefixes and so keep their tables from growing indefinitely(or too
> > excessively, exponentially). Instead, they would advertise the AS
> numbers.
> > In fact, a AS number can be seen as an aggregated identifier of all the
> IDs
> > inside the AS's domain.
>
> In most of the past conversation: "ID" has meant the equivalent
> (loosely) of 'interface ip address' or 'interface attachment point'
> "Locator" has meant
> the equivalent (loosely) of 'ASN'
>
> My reading of the initial quote did not match the above 2 items.
>
Actually, I'm new to this group, so don't have the collected knowledge of
past conversations. My sincere apology.
By ID here, I mean the ID of the host. This ID is to be used in Transport
connections with its peer. But it is not meant for routing.
Locator, by contrast, is for the interface, as you say, or
PoA(point-of-attachment).
I intentionally try not to use the term 'address' or 'IP address', since in
the current Internet, the IP address is used as both ID and Locator.
>
> > 2. IMHO, there's no compelling reason why the locators should be
> global,
> > in network architectural sense.
> >
> > o All over the world, the street numbers would be sequenced from
> 1
> > to 100 or the like. They are local, but we don't have problems to
> reaching
> > someone we want.
>
> 'locator' in the sense of a mailing address (in the us) would be some
> combination of: ZipCode + town.
> 'identifier' in the sense of a mailing address (in the us) would be
> 'house-number' (or street number + apartment number).
>
No. 'house #' (street # + apt #) is still part of the locator to my
definition. Instead, your name on the envelope would be the ID in my
context.
> > o How global is 'global'? What are we going to do about the
> > inter-planetary Internet? How about the spaceships on the moon or the
> Mars?
>
> I'm not sure geography matters here... network topology does.
>
Even in topology, how large is going to be your topology?
But, in fact, this is not the real point. Independently of the question of
the network size, there's no compelling network architectural reason for the
locator to be global in achieving the task of reaching (routing) to the
destination.
e2e routing can be done in a network of concatenated ASs each with local
locators.
> > o Delivering packets, tagged with ID, to a regional authority in
> > charge of locating the objects within its region is enough to reach a
> > targeted receiver.
>
> 'tagged with locator' to the region, taking the identifier once it's
> inside the 'region' for final delivery to the end system.
>
No, the reverse. A packet in IDR(inter-domain routing) will only be tagged
with an ID of a target destination host. Once the packet arrives at an
ingress gateway (IDR router) into the AS the target host belongs to, the
packet will then be appended with a local locator of the AS ('region' in
your terminology). The local 'id-to-loc' (also serves as 'as-to-loc') mapper
provide the local locator to the target host.
>
> -Chris
>
I'm attaching the revised summary of my idea with the hope that it provides
a better picture of what I have in mind.
--
Regards,
DY
http://cnu.kr/~dykim
SCALABLE INTERNET
dykim, 09.11
A. Fundamentals:
o Skeletons:
o ID is global, Locator is local(private) to AS.
o Keep use of DNS, with some extension.
o TCP works on ID, IP on Loctor, Gateways(BGP) on AS #.
o Gateways advertises only AS #s, not network prefixes.
o Corollaries:
o Number space of AS is limited to 2^^16(64K) in one tier.
o AS tier recurs hierarchically, downward and upwards(or inwards and
outwards). In each tier, the maximum number of ASs is limited to 2^^16.
o AS(cloud) can float within and across tiers. AS(ISP) can change is
neighbor relation anytime in the course of its existence within and across the
tier architecture.
o Implementation choices:
o Take IPv4 and IPv6 addresses as IDs. That is, IP addresses in the
current Internet infrastructure is to be used as IDs, not anymore as locators.
o Locators are local (private) IP addresses.
o DNS is extended to serve not only name-to-address(ID) mapping but
also ID-to-AS mapping.
o Mapping between AS and (local) Locator, forward as well as reverse,
is done by a server(LocS) within the AS where the affected hosts or gateways
belong.
B. Scenario of outgoing communication example:
1. DNS returns the remote (glabal) ID as well as the AS number it belongs
to.
2. TCP establishes connections by use of ID.
3. TCP requests, to IP, transmission of segments with the AS number, as a
parameter, of the domain where the destination peer belongs.
4a. If the target AS is foreign, IP uses a locator to deliver the packet to
the egress gateway(BGP) router.
4b. If the target AS is local, IP uses a locator(private IP address) to
deliver the packet. The target can be a local host or the ingress router into a
local internal AS belonging to one lower(deeper) tier.
5. Local gateway relays the packet to one of the next hop gateways that
advertised the target AS #.
C. Scenario of incoming communication example:
1. If the AS of the incoming packet is a foreign one for which the
receiving AS has contracted for transit, the packet is redirected to a relevant
outgoing gateway.
2. If the AS of the incoming packet is indeed local, the ingress gateway
delivers the packet to the target implied by the ID imbedded in the packet. The
resultant target can be a local host or an ingress router into a local internal
AS beloning to one lower(deeper) tie.
D. Consequences
o Gateway routing table doesn't explode, never exceeds 64K(2^^16).
o AS tier can recurs, theoretically, indefinitely. The whole Internet can
scale to infinity.
o NAT is a norm, not an evil.
o The current IP address management infrastructure won't be abandoned. They
operate exactly the same way as it does. Only that the number is now used as
IDs, not for locators.
o The current DNS infrastructure is maintained, only with a bit of
extension. It now has to keep database of (domain name, ID, AS number) tuples.
o Minimal disturbance to the current Internet infrastructure, with a path
out for sustainable scalability.
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