RFC relevance of encapsulation

As per Relevance of the word encapsulation, we have this rfc below:

Network Working Group P. Newman,
Request for Comments: 1954 W. L. Edwards,
Category: Informational R. Hinden,
E. Hoffman,
F. Ching Liaw,
T. Lyon,
G. Minshall,
May 1996

Transmission of Flow Labelled IPv4 on ATM Data
Ipsilon Version 1.0

Status of this

This document provides information for the Internet community.
memo does not specify an Internet standard of any kind.
of this memo is unlimited

IESG Note

This note documents a private protocol for IPv4-based flows.
protocol is NOT the product of an IETF working group nor is it
standards track document. It has not necessarily benefited from
widespread and in depth community review that standards
documents receive

This document specifies the manner for transmitting IPv4
over an ATM data link, both in a default manner and in the
of flow labelling via Ipsilon Flow Management Protocol [IFMP].

Table of

Introduction....................................................2
1. Labels.......................................................2
2. Default Encapsulation........................................2
3. Flow Type 0 Encapsulation....................................3
4. Flow Type 1 Encapsulation....................................4
5. Flow Type 2 Encapsulation....................................5
References......................................................7
Security Considerations.........................................7
Authors' Addresses..............................................7

Newman, et. al. Informational [Page 1]

RFC 1954 Flow Labelled IPv4 on ATM May 1996

This document specifies the manner for transmitting IPv4
over an ATM data link, both in a default manner and in the
of flow labelling via Ipsilon Flow Management Protocol [IFMP].
specific functions such as OAM cells, the CLP bit, and ABR RM
are not used. There are no reserved VCIs other than VPI = 0, VCI =
0, which indicates an unassigned cell; and VPI = 0, VCI = 15,
is used for the default encapsulation. IFMP messages must be
using the default encapsulation

1.

Labels, as carried by IFMP, are realized on an ATM data link
specific VPI/VCIs. The format of the Label field for ATM labels is

0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|Reservd| VPI | VCI |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

The low order 16 bits of the label correspond to the VCI, with
least significant bit of the Label field corresponding to the
significant bit of the VCI. If the link cannot support a full 16
VCI the unused bits of the VCI must be the most significant bits
they must be set to zero

The next 12 higher order bits of the label correspond to the VPI
with the least significant of these bits corresponding to the
significant bit of the VPI. If the link cannot support a full 12
VPI, then the unused bits of the VPI must be the most
bits and they must be set to zero. The most significant four bits
the label are reserved. They should be set to zero by the sender
ignored by the receiver

2. Default

The default encapsulation for IPv4 packets on ATM data links is
LLC/SNAP encapsulation specified in section 4.1 "LLC
for routed protocols" of RFC 1483 [RFC1483]. Such frames begin
the octets 0xAA 0xAA 0x03 0x00 0x00 0x00 0x08 0x00 (the LLC/
header for IPv4). The LLC/SNAP header is prefixed to the IP
and the entire packet is encapsulated within the payload of an AAL-5
CPCS-PDU as specified in RFC 1483 and illustrated below

Newman, et. al. Informational [Page 2]

RFC 1954 Flow Labelled IPv4 on ATM May 1996

0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| LLC (0xAA-AA-03) | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| SNAP (0x00-00-00-08-00) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
~ IPv4 Datagram ~
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Pad (0 - 47 octets) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
+ AAL-5 CPCS-PDU Trailer (8 octets) +
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

The maximum transmission unit (MTU) of an IPv4 datagram using
default encapsulation is 1500 octets

Frames using the default encapsulation are sent to: VPI = 0, VCI =
15.

3. Flow Type 0

All IPv4 frames using Flow Type 0 are encapsulated within the
of an AAL-5 CPCS-PDU. This is the null encapsulation of section 5.1
"VC based multiplexing of routed protocols" from RFC 1483 [RFC1483].
There is no LLC/SNAP header. The first octet of the
corresponds to the first octet of the IPv4 datagram (i.e., the
that contains the IP version number (4) and Internet Header
(IHL) ). The IP datagram is encapsulated within the payload of
AAL-5 CPCS-PDU as specified in RFC 1483 and illustrated below

Newman, et. al. Informational [Page 3]

RFC 1954 Flow Labelled IPv4 on ATM May 1996

0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
~ IPv4 Datagram ~
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Pad (0 - 47 octets) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
+ AAL-5 CPCS-PDU Trailer (8 octets) +
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

The MTU of an IPv4 datagram using Flow Type 0 encapsulation is 1500
octets

Frames using Flow Type 0 encapsulation are sent to the VPI/
specified in the Label field of the corresponding IFMP Flow Type 0
Redirect message element [IFMP].

4. Flow Type 1

All IPv4 frames using Flow Type 1 are encapsulated directly in
payload of an AAL-5 CPCS-PDU. This is the null encapsulation
section 5.1 "VC based multiplexing of routed protocols" from RFC 1483
[RFC1483]. There is no LLC/SNAP header. Also, the following
of the IP header are not transmitted: Version, Internet Header
(IHL), Type of Service (TOS), Time to Live (TTL), Protocol,
Address, and Destination Address. In addition, the first 4
immediately following the IP header (as determined by the IHL field
are not transmitted. (These 4 octets correspond to the source
destination ports for TCP and UDP datagrams.) The value of the
Length field is not changed; it remains the total length of the
datagram before the above fields were removed. The transmitted
of the Checksum field is the checksum value that would have
computed for the entire IP header if the TTL field had been set
zero (i.e., the actual value of the TTL field is "subtracted",
one's-complement arithmetic, from the Checksum before transmission).

The IP datagram is encapsulated within the payload of an AAL-5 CPCS
PDU as specified in RFC 1483 and illustrated below

Newman, et. al. Informational [Page 4]

RFC 1954 Flow Labelled IPv4 on ATM May 1996

0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Total Length | Identification |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|Flags| Fragment Offset | Checksum |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
~ Data ~
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Pad (0 - 47 octets) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
+ AAL-5 CPCS-PDU Trailer (8 octets) +
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

The MTU of the IPv4 datagram using Flow Type 1 encapsulation is 1484
octets (1500 octets minus the 16 octets specified above).

Frames using Flow Type 1 encapsulation are sent to the VPI/
specified in the Label field of the corresponding IFMP Flow Type 1
redirect message element [IFMP].

5. Flow Type 2

All IPv4 frames using Flow Type 2 are encapsulated directly in
payload of an AAL-5 CPCS-PDU. This is the null encapsulation
section 5.1 "VC based multiplexing of routed protocols" from RFC 1483
[RFC1483]. There is no LLC/SNAP header. Also, the following
of the IP header are not transmitted: Version, Internet Header
(IHL), Time to Live (TTL), Source Address, and Destination Address
The first 4 octets immediately following the IP header (as
by the IHL field) are transmitted. (These 4 octets correspond to
source and destination ports for TCP and UDP datagrams.) The value
the Total Length field is not changed; it remains the total length
the IP datagram before the above fields were removed.
transmitted value of the Checksum field is the checksum value
would have been computed for the entire IP header if the TTL
had been set to zero (i.e., the actual value of the TTL field
"subtracted", using one's-complement arithmetic, from the
before transmission).

The IP datagram is encapsulated within the payload of an AAL-5 CPCS
PDU as specified in RFC 1483 and illustrated below

Newman, et. al. Informational [Page 5]

RFC 1954 Flow Labelled IPv4 on ATM May 1996

0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Reserved |Type of Service| Total Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Identification |Flags| Fragment Offset |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Reserved | Protocol | Checksum |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
~ Data ~
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Pad (0 - 47 octets) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
+ AAL-5 CPCS-PDU Trailer (8 octets) +
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

The Reserved fields are not used and should be set to zero by
sender and ignored by the receiver

The MTU of the IPv4 datagram using Flow Type 2 encapsulation is 1492
octets (1500 octets minus the 8 octets specified above).

Frames using Flow Type 2 encapsulation are sent to the VPI/
specified in the Label field of the corresponding IFMP Flow Type 2
redirect message element [IFMP].

Newman, et. al. Informational [Page 6]

RFC 1954 Flow Labelled IPv4 on ATM May 1996

[IFMP] Newman, P., et. al., "Ipsilon Flow Management
Specification for IPv Version 1.0", Ipsilon
Inc., RFC 1953, May 1996.

[RFC1483] Heinanen, J., "Multiprotocol Encapsulation over
Adaptation Layer 5", RFC 1483, July 1993.

SECURITY

Security issues are not discussed in this document

AUTHORS'

Peter Newman Phone: +1 (415) 846-4603
Ipsilon Networks, Inc. EMail: pn@ipsilon.

W. L. Edwards, Chief Scientist Phone: +1 (913) 534 5334
Sprint EMail: texas@sprintcorp.

Robert M. Hinden Phone: +1 (415) 846-4604
Ipsilon Networks, Inc. EMail: hinden@ipsilon.

Eric Hoffman Phone: +1 (415) 846-4610
Ipsilon Networks, Inc. EMail: hoffman@ipsilon.

Fong Ching Liaw Phone: +1 (415) 846-4607
Ipsilon Networks, Inc. EMail: fong@ipsilon.

Tom Lyon Phone: +1 (415) 846-4601
Ipsilon Networks, Inc. EMail: pugs@ipsilon.

Greg Minshall Phone: +1 (415) 846-4605
Ipsilon Networks, Inc. EMail: minshall@ipsilon.

Newman, et. al. Informational [Page 7]

RFC 1954 Flow Labelled IPv4 on ATM May 1996

Ipsilon Networks, Inc. is located at

2191 East Bayshore
Suite 100
Palo Alto, CA 94303

Sprint is located at

Sprint Technology Services - Long Distance
9300 Metcalf
Mailstop KSOPKB0802
Overland Park, KS 66212-6333

Newman, et. al. Informational [Page 8]

if you see any problems within the linking, don't worry be happy,
this is version 0.1 of the Relevance System and you gotta expect some crappy subroutines sometimes,
just be content we did not write this in Java, which would have made this "bigger and better" HAHAHHA.

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