Hi, Owen:
0) I am glad that you do not object to the notion that two premises
on an RAN can establish end-to-end connectivity via L2 routing.
1) For a better visualization, the below derivation will make use of
figures in the EzIP Draft:
https://datatracker.ietf.org/doc/html/draft-chen-ati-adaptive-ipv4-address-space
A. As I stated, premises on RAN1 (served by SPR1 -
69.41.190.110)and premises on RAN4 (served by SPR4 - 69.41.190.148) in
Figure 1 can communicate with one another via L2 routing based on 240/4,
respectively. Since the 240/4 pool is large enough to serve the entire
population of most countries, each needs only one RAN to provide the
basic end-to-end connectivity for daily life of all citizens. Thus,
Intra-RAN direct connectivity is provided.
B. Similarly, SPR1 (69.41.190.110)and SPR4 (69.41.190.148)can
communicate with each other by L2 routing via the Internet core routers
(utilizing plain IPv4 headers as well).
C. For T1z (192.168.1.9) on Premises 1 (240.0.0.0) to
communicate with IoT T4z (246.1.6.40), we will need to extend the plain
IPv4 header used in Step B. above by utilizing RFC791 to carry the 240/4
addresses as Option words. Figure 16 shows an EzIP header configured for
such a situation. Note that Word 9 represents the port numbers of IoTs
on RGs. Since T4z is an IoT directly connect to SPR4, only the value
(9N) for T1z is meaningful.
D. An IP packet with header in the form of Figure 16 can be
delivered, if
a. Routers between SPR1 and SPR4 will treat it as a plain
IPv4 packet (i.e., ignoring the Option words), and,
b. SPRs recognize the Option words and make use of then to
route the packets across the RANs.
2) For Step 1) D. a., it is said that many network routers drop
packets having Option word due to certain security ("IP Source Route"
attacks?) concerns. Although, there have been reports that such packets
did get through certain routes anyway. This scheme is similar as those
dropping 240/4 addressed packets. So, disabling such mechanism along the
desired path may be feasible.
3) For Step 1) D. b., enhanced SPR programs will be needed to
recognize the Option words for utilizing them to route when the
inter-RAN direct connectivity mode is activated.
So, direct world-wide end-to-end connectivity is possible based
on the EzIP scheme.
4) However, economics comes into play when considering to deploy Step
1) D. at this juncture. Since the Internet has evolved into the
predominantly CDN model whose architecture is a master-slave hierarchy,
subscribers desiring for direct inter-RAN connectivity is likely a much
smaller subset among those desiring for Intra-RAN connectivity. This is
like comparing international mail versus the domestic counter part. It
may be difficult to justify efforts for Steps 2) & 3), before the demand
becomes universal upon the general public realizing the possible
functions. Instead, one of the old PSTN practices may be mimicked here
as the interim solution. That is, the telephony "Foreign Exchange" setup
used to enable a subscriber at distance to appear on local telephone
services. It was achieved by permanently "nailed-up" a telephone
extension wiring (started from a pair of actual physical copper wires in
the earlier days to a dedicated voice channel in a digital multiplex
environment) to a business that is remote from a community it serves. I
am sure that the equivalent capability already exists in the Internet
and is being used somewhere. This can be utilized to set up the
extension link between any two RANs having the need.
Regards,
Abe (2024-01-24 12:28 EST)
On 2024-01-20 13:23, Owen DeLong wrote:
No. No matter how you cobble it, IPv4 doesn’t have enough addresses to
restore proper end to end connectivity.
Owen
On Jan 20, 2024, at 07:36, Abraham Y. Chen wrote:
Hi, Owen:
1) " ... IPv4 used to work before NAT made everything horrible. ":
Utilizing 240/4, RAN is a flat space which should support this
kind of rudimentary end-to-end connectivity within each RAN. (called
L2 routing, correct?)
Regards,
Abe (2024-01-20 10:35)
On 2024-01-19 04:02, Owen DeLong wrote:
Any host connected to a reasonably well peered ISP (e.g. NOT Cogent)
with IPv6 should be able to communicate with any other such host so
long as the administrative policies on both sides permit it.
I have no difficulty directly reaching a variety of IPv6 hosts from
the /48 in my home.
However, it’s not like dial-up modem operations in the PSTN in that
IP is an inherently connectionless packet switched service while
modems were an inherently circuit switched connection oriented service.
However, it does work like IPv4 used to work before NAT made
everything horrible.
Owen
On Jan 15, 2024, at 12:20, Abraham Y. Chen wrote:
Hi, Forrest:
1) I have a question:
If I subscribe to IPv6, can I contact another
