# Space use of Internet protocols at network layer and above

Space missions using Internet addresses and transport protocols for any
communication functions (e.g., onboard , inter-spacecraft ,
space-to-ground, space-to-end system) are required to support at least
the Internet Protocol (IP) standard, RFC 791, for packet structure and
addressing. This requirement ensures compatibility and interoperability
with other systems both onboard and within the ground network
infrastructure. These protocol definitions apply to both onboard and
space to ground links. The mapping of these common, end-to-end protocols
to specific onboard and space to ground data links is discussed in later
sections.

RFC 791 - Internet Protocol - September 1981, Internet Engineering Task
Force

It is also recommended that systems using IP also support the Internet
Control Message Protocol standard, RFC 791 for network control and
status messages.

RFC 792 - Internet Control Message Protocol - September 1981, Internet
Engineering Task Force

The standard protocols for use above the network layer are the
Transmission Control Protocol (TCP, RFC-793) and the User Datagram
Protocol (UDP, RFC-768). These provide multiplexing of data streams and
TCP provides "reliable" data delivery.

RFC 793 - Transmission Control Protocol - September 1981, Defense
Advanced Research Projects Agency

RFC 768 - User Datagram Protocol - August 1980, Internet Engineering
Task Force

The current version of IP is version 4, a new version (v6) is being
developed and the corresponding versions for the network protocol are
available as the following draft standards.

RFC 2460 - Internet Protocol, Version 6 (IPv6) Specification - December
1998

RFC 2463 - Internet Control Message Protocol (ICMPv6) for the Internet
Protocol Version 6 (IPv6) Specification - December 1998

All Internet standards can be accessed through the Internet Engineering
Task Force (IETF) web site at <http://www.ietf.org/rfc.html>.

# Space use of Internet protocols over onboard data links

Space missions using Internet Protocol (IP) packets over onboard data
links should use the following specifications to ensure compatibility
and interoperability between onboard systems and with the ground
network. The currently identified onboard interface types and associated
framing mechanisms are:

-   Serial clock and data (e.g. RS-422) with HDLC framing

-   Ethernet with Ethernet type 2 framing

-   IEEE 1394, Standard for a High Performance Serial Bus

## Serial clock and data interface with HDLC framing

Systems using serial interfaces will use the High-Level Data Link
Control (HDLC) framing mechanism and the Multiprotocol Interconnect over
Frame Relay encapsulation format for carrying IP packets over the link.
This interface is identical to the space-to-ground formats for serial
links.

RFC 2427 - Multiprotocol Interconnect over Frame Relay - September 1998,
Internet Engineering Task Force.

ISO/IEC 3309:1991(E), \"Information Technology - Telecommunications and
information exchange between systems - High-level data link control
(HDLC) procedures - Frame structure\", International Organization For
Standardization, Fourth edition 1991-06-01.

## Ethernet with Ethernet type 2 framing

Systems using Ethernet local area networks (LANs) will use the standard
Internet mechanisms for encapsulating IP packets over Ethernet and
resolving IP and Ethernet addresses.

RFC894 - A Standard for the Transmission of IP Datagrams over Ethernet
Networks - April 1984, Internet Engineering Task Force

RFC826 - An Ethernet Address Resolution Protocol - November 1982,
Internet Engineering Task Force

## IEEE 1394

Systems using IEEE 1394-1995, Standard for a High Performance Serial
Bus, as a local area network (LAN) will use the currently defined
mechanism for encapsulating IP packets over IEEE 1394.

RFC2734 - IPv4 over IEEE 1394 - December 1999, Internet Engineering Task
Force

All Internet standards can be accessed through the Internet Engineering
Task Force (IETF) web site at <http://www.ietf.org/rfc.html>.

# Space use of Internet protocols over wireless data links

Space missions using Internet Protocol (IP) packets over wireless data
links (e.g. RF or optical) should use the following specifications to
ensure compatibility and interoperability. The following interface types
have currently been identified

-   Clock and data serial bitstream with HDLC framing

The encapsulation and framing of the IP packets will be handled
independently of any modulation (e.g. BPSK, QPSK) and coding (e.g.
convolutional, Reed-Solomon, BCH) mechanisms. Any framing needed to
implement the coding, such as Reed-Solomon, will be completely
independent of the data link framing used to encapsulate the IP packets.
The only function of the coding will be to operate on the bitstream
being delivered. The coding and modulation will be added and removed
transparently to the bitstream carrying the framing of the IP packets.

## Clock and data serial bitstream with HDLC framing

Systems sending and receiving IP packets over clock and data serial
interfaces will use the High-Level Data Link Control (HDLC) framing
mechanism and the Multiprotocol Interconnect over Frame Relay
encapsulation format for carrying IP packets over the link. This
interface is identical to the onboard formats for serial links.

RFC 2427 - Multiprotocol Interconnect over Frame Relay - September 1998,
Internet Engineering Task Force.

ISO/IEC 3309:1991(E), \"Information Technology - Telecommunications and
information exchange between systems - High-level data link control
(HDLC) procedures - Frame structure\", International Organization For
Standardization, Fourth edition 1991-06-01.

All Internet standards can be accessed through the Internet Engineering
Task Force (IETF) web site at <http://www.ietf.org/rfc.html>.