The Transmission of IP Datagrams over the SMDS Service
RFC 1209
| Document | Type |
RFC - Internet Standard
(March 1991; No errata)
Also known as STD 52
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|---|---|---|---|
| Last updated | 2013-03-02 | ||
| Stream | IETF | ||
| Formats | plain text pdf html bibtex | ||
| Stream | WG state | (None) | |
| Document shepherd | No shepherd assigned | ||
| IESG | IESG state | RFC 1209 (Internet Standard) | |
| Consensus Boilerplate | Unknown | ||
| Telechat date | |||
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Network Working Group D. Piscitello
Request for Comments: 1209 J. Lawrence
Bell Communications Research
March 1991
The Transmission of IP Datagrams over the SMDS Service
Status of this Memo
This memo defines a protocol for the transmission of IP and ARP
packets over a Switched Multi-megabit Data Service Network configured
as a logical IP subnetwork. This RFC specifies an IAB standards
track protocol for the Internet community, and requests discussion
and suggestions for improvements. Please refer to the current
edition of the "IAB Official Protocol Standards" for the
standardization state and status of this protocol. Distribution of
this memo is unlimited.
Abstract
This memo describes an initial use of IP and ARP in an SMDS service
environment configured as a logical IP subnetwork, LIS (described
below). The encapsulation method used is described, as well as
various service-specific issues. This memo does not preclude
subsequent treatment of the SMDS Service in configurations other than
LIS; specifically, public or inter-company, inter-enterprise
configurations may be treated differently and will be described in
future documents. This document considers only directly connected IP
end-stations or routers; issues raised by MAC level bridging are
beyond the scope of this paper.
Acknowledgment
This memo draws heavily in both concept and text from [4], written by
Jon Postel and Joyce K. Reynolds of ISI and [5], written by David
Katz of Merit, Inc. The authors would also like to acknowledge the
contributions of the IP Over SMDS Service working group of the
Internet Engineering Task Force.
Conventions
The following language conventions are used in the items of
specification in this document:
o MUST, SHALL, or MANDATORY -- the item is an absolute
requirement of the specification.
IP over SMDS Working Group [Page 1]
RFC 1209 IP and ARP over the SMDS Service March 1991
o SHOULD or RECOMMENDED -- the item should generally be followed
for all but exceptional circumstances.
o MAY or OPTIONAL -- the item is truly optional and may be
followed or ignored according to the needs of the implementor.
Introduction
The goal of this specification is to allow compatible and
interoperable implementations for transmitting IP datagrams and ARP
requests and replies.
The characteristics of the SMDS Service and the SMDS Interface
Protocol (SIP) are presented in [3], [6], and in [7]. Briefly, the
SMDS Service is a connectionless, public, packet-switched data
service. The operation and features of the SMDS Service are similar
to those found in high-speed data networks such as LANs:
o The SMDS Service provides a datagram packet transfer, where each
data unit is handled and switched separately without the prior
establishment of a network connection.
o The SMDS Service exhibits high throughput and low delay, and
provides the transparent transport and delivery of up to 9188
octets of user information in a single transmission.
o No explicit flow control mechanisms are provided; instead, the
rate of information transfer on the access paths is controlled
both in the subscriber-to-network direction and in the network-
to-subscriber direction through the use of an access class
enforcement mechanism.
o Both individually and group-addressed (multicast) packets can
be transferred.
o In addition to these LAN-like features, a set of addressing-
related service features (source address validation, source and
destination address screening) are provided to enable a
subscriber or set of subscribers to create a logical private
network, or closed user group, over the SMDS Service. The
access control provided by the closed user group mechanism is
supplied by the SMDS provider according to the specifications
stated in [3].
o SMDS addresses are 60 bits plus a 4 bit Address Type. The
Address Type subfield occupies the 4 most significant bits of
the destination and source address fields of the SIP Level 3
Protocol Data Unit (PDU). It contains the value 1100 to
IP over SMDS Working Group [Page 2]
RFC 1209 IP and ARP over the SMDS Service March 1991
indicate an individual address and the value 1110 for a 60-bit
group address.
The SMDS Interface Protocol is based on the IEEE Standard 802.6,
Distributed Queue Dual Bus (DQDB) Connectionless MAC protocol [8].
The SMDS service layer corresponds to the IEEE 802 MAC sublayer. The
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