+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
+ Destination TA +
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
+ Source TA +
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Destination Port Number | ver |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Source Port Number | QoS |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Length | Checksum |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
/ Data /
\ : \
/ : /
\ : \
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Destination TA: 64 bits.
The Destination Transport Address. The concatenation of
the 24 bit IEEE assigned Ethernet address and the 40 bit
representation of the machines serial number for the remote
node.
Source TA: 64 Bits.
The Source Transport Address. The concatenation of the 24
bit IEEE assigned Ethernet address and the 40 bit
representation of the machines serial number for the local
node.
Destination Port Number: 28 Bits.
Identifies the specific application on the remote node.
Ver: 4 bits.
This parameter the UDP version number in use within this
packet.
Source Port Number: 28 Bits.
Identifies the specific application on the local node.
QoS: 4 bits.
The Quality of Service parameter may be set by the user
application and passed down to a network layer that
supports different levels of service.
Length: 16 bits
The length parameter represents the length of the data area
in octets. This value will be set to zero if no data is
sent within this packet.
Checksum: 16 bits
The checksum parameter has the same meaning as in the
current version of UDP. The current 96 bit pseudo header
is NOT used in calculating the checksum. The checksum
covers only the information present in this header. The
checksum field itself is set to zero for the calculation.
Data: Variable
This is the area in which the data for the datagram will be
sent. The length of this data in octets is specified by
the length parameter above.
Appendix D
______ ______
| | | |
| H1 | | H2 |
| | | |
|______| |______|
\ / \
\ / \
========================= / \
" "/ |
" (SIPP) " |
" " |
"=========================" |
|
====================
______ " "
| | " CLNP "
| H4 | " "
| | "===================="
|______| |
\ |
\ |
=================== ___|___
" " | |
" "-------| H3 |
" IPv4 " | |
" " |_______|
"=================="
Example 1: H1 Wishes to Establish Communication with H4 (Refer to the
figure above.)
1. A user on host H1 attempts to communicate with a user
on host H4 by referencing H4 s fully qualified domain name.
2. The TCP on H1 makes a DNS call to determine the TA
address of H4.
3. The DNS call returns only the IPv4 address since H4 is
determined to be an IPv4 only host.
4. The H1 TCP builds a transmission control block (TCB)
setting the C-Bit (compatibility) "ON" since H4 is an IPv4
host. Included in the TCB will also be DA = IP-H4, SA =
TA1, DP = 1234, SP = 5000 and any state parameters
describing the connection (port numbers are for example
purposes only).
5. The IP on H1 makes a DNS call to determine the network
IP address of H4 and correspondingly caches both the TA
address from the TCP as well as the network IP address for
later use.
6. The packet is now routed using standard SIPP procedures
to H2 this is the only path H1 has to H4.
7. H2 receives the packet from H1. The TCP on H2 checks
the destination TA of the packet and compares it to its
own. In this case it does not match, therefore the packet
should be forwarded.
8. H2 s TCP will interrogate the supported network
layer(s) and determines the packet must be forwarded to H3.
9. The TCP must now pass the packet the CLNP network
layer. The network layer checks its cache to determine if
there is a route specified for DA = IP-H4 already in the
cache. If so the cache entry is used, if not an entry is
created. H2 then routes the packet to H3 via NA3a, which
is the network layer address for IP-H4.
10. H3 receives the packet from H2. The TCP on H3 checks
the destination TA of the packet and compares it to its
own. Once again, it does not match.
11. H3, realizing that the destination address is an IPv4
host, and knowing that it itself is directly connected to
the IPv4 network constructs an IPv4 compatible header. H3
also constructs a TCB to manage the IPv4 connection.
12. The packet is sent down to be routed to the IP using
standard IP routing procedures.
13. H4 receives the packet at which point the IP on it
determines that the destination address is its own and thus
proceeds to strip off the IP header and pass the packet up
to the TCP layer.
14. The TCP layer than opens the corresponding IPV4_DP
port (2311) which forms the first half of the connection to
the application.
15. H4 will now reply with a connection accept message,
sending the packet back to H3.
16. H3 s TCP receives the packet and based on information
in the TCB determines the packet should be delivered to H1.
H3 uses the steps outlined above to route the packet back
through the network structure.
Example 2: H2 Wishes to Establish Communication with H3 (Refer to the
figure above.)
1. A user on host H2 attempts to communicate with a user
on host H3 by referencing H3 s fully qualified domain name.
2. The TCP on H2 makes a DNS call to determine the TA
address of H3.
3. The DNS call returns the TA address for H3.
4. The H2 TCP builds a transmission control block (TCB)
setting the C-Bit (compatibility) "OFF" since H3 is an IPng
host. Included in the TCB will also be DA = TA3, SA = TA2,
DP = 1111, SP = 2222 and any state parameters describing
the connection (port numbers are for example purposes
only).
5. The IPng on H2 makes a DNS call to determine the
network IPng address of H3 and correspondingly caches both
the TA address from the TCP as well as the network IPng
address for later use.
6. The packet is now routed to H3 over the IPng supported
on that network.
7. H3 receives the packet from H2. The TCP on H3 checks
the destination TA of the packet and compares it to its
own. In this case it matches.
8. H3 s TCP will construct a TCB and respond with an open
accept message.
9. H3 s TCP will interrogate the supported network
layer(s) to determine the packet must be delivered to H2
using NA2b which is specified in its cache.
Security Considerations
Security issues are not discussed in this memo.
Authors' Addresses
Richard Carlson
Argonne National Laboratory
Electronics and Computing Technologies
Argonne, IL 60439
Phone: (708) 252-7289
EMail: RACarlson@anl.gov
Domenic Ficarella
Motorola
Phone: (708) 632-4029