...environment

As opposed to a research environment, where the failure of the technology is expected and studied, rather than feared.

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...RFC 2022

At the time this problem statement was written, RFC 2022 was not yet approved as RFC, but still a draft proposal.

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...electronic

In this thesis, a lot of  references are made to documents made available by others on the  Internet. This is done in the form of  Universal Resource Locators ( URLs). The documents are available at the time of the printing of this document, but may be (re)moved at any time beyond the author's control. This may be a fragile basis for references, but in most cases, considering the nature of the documents, they will be available for a long time. An attempt will be made to have the documents referred to in this thesis and a  HTML version of this thesis added to stable  web-sites related to this field.

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...suite

TCP/IP is named after the two most important protocols in the suite;  Transmission Control Protocol ( TCP) and   Internet Protocol ( IP).

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...Internet

The Internet is used here to indicate that particular internet (the one we know and use for e-mail and such), the term internet without a capital `I' is used for a generic network based on the TCP/IP protocol suite

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...service

Later on, the ``cloud'' will be used to represent two or even more of the lower layers together, so this is not always true.

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...ICMP

See Figure 2.8 for an explanation of the acronyms

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...function

In a multicast capable IP implementation only

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...NAME=355> IANA

IANA: Internet Assigned Numbers Authority. http://www.iana.org/

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...regional

Three regions exist: RIPE http://www.ripe.net/, InterNIC http://www.internic.net/ and
APNIC http://www.apnic.net/

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...2

URL: http://www.internic.net/std/std2.txt

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...layer

In these examples, this representation introduces a slight inconsistency with the  TCP/IP implementation model as shown in Figure 2.8. Since this image is used to explain ARP, the reader is encouraged to apply some imagination to integrate this with the TCP/IP implementation model.

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...(15#15

This is a label in the time-sequence diagram.

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...NAME=438> LIS

A LIS is the logical ATM equivalent of a LAN

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...server

In this example ATM connection setup details are ignored

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...HREF="node6.html#ARProuter">2.12

This is not a very `correct' representation of the actual `calls for service', but for the purpose of understanding how ARP works in this situation with a router it is sufficiently clear.

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...that

Later a similar way will be used in the description of the ATM protocol stack

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...router

This does require additional configuration on the host

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...LANs

Although the network may also be a backbone link across an ocean, since it has the same functionality as a Local Area Network, it is still called a LAN.

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...IPng

IPv6 is the preferred way to refer to the new protocol), more information about IPv6 can be found in [DH95]

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...knows

The multicast routing protocols make sure the routers can know this, but how they work is outside the scope of this thesis. Further details on multicast routing can be found in http://www.3com.com/nsc/501303.html. The most common multicast routing protocol is DVMRP, which works by first broadcasting to all reachable mrouters. When no members are connected to a branch, the branch is pruned from the tree. The broadcast from the source may reach a router from several directions, the shortest of which is then selected.

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...Processes

Processes make use of UDP to access the multicast functions, multiple processes may join the same host group on a single host

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...address

this mapping is not one to one, but one IP address maps to 32 Ethernet multicast addresses. This is because only the lower 23 bits of the IP address are used, where 28 are significant for an IP multicast address

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...IGMP

parts of this section are copied from 3Com's document at URL: http://www.3com.com/nsc/501303.html

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...ATM

The ATM-Linux implementation has no support for native multicasting at this time, but other ATM implementations do have some support for multicasting.

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...all

``All nodes'' may be a bit exaggerated, IPv6 packets could be tunneled like IP multicast packets.

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...MBone

at the time of this writing, the MBone has approximately 30,000 users (see the June 1997 issue of ``Byte'' magazine, in the article ``Multicasting to the Masses'')

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...medium

Although lower bandwidth ATM systems do exist, e.g. for wireless LANs

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...cables

The same Category 5 UTP cables as used for Ethernet 10(0)Base-T networks

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...NAME=780> Cell

The Cell is the Protocol Data Unit (PDU) for the ATM layer.

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...octets

One octet is 8 bits, also known as a byte.

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...are

See [UNI31] for specific details.

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...D

Class D is the Connectionless Service Class, according to the Broadband ISDN related ITU-T Recommendations

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...NAME=823> Re-assembly

Segmentation And Re-assembly, SAR

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...Entities

The VPL and  VCL also end at the end of a Connection (VPC and VCC respectively)

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...HREF="node8.html#ATMVC">4.3

The original of this figure was made by Fokke Hoeksema

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...procedures

The address registration procedures are defined in section 5.8 of [UNI31]

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...``Phase 1''

Phase 1 is the term used in the UNI 3.1 specification for the protocol defined therein. In [UNI40], this term is not repeated, therefore I conclude that it has either not changed or the term is deprecated.

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...CSMA-CD

CSMA-CD: Carrier Sense, Multiple Access with Collision Detection

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...Linux''

last known download location: ftp://viulu.atm.tut.fi/pub/misc/linux-lane.ps.gz.

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...NBMA

NMBA; Non-Broadcast Multi-Access networks

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...efficient

Actually, it would not be efficient if the transmission would be very short, the criteria are discussed in the draft mentioned and [SM97]

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...NAME=1054> LLC/SNAP

Logical Link Control (LLC), SubNetwork Attachment Point (SNAP)

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...quickly

The available draft, linked here is not complete and is about to expire at the time of this writing

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...thesis

RFC 2022 is a general layer 3 multicast over ATM specification, but uses IP as layer 3 example

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...hosts

How the addresses of this group is acquired is discussed in the section about multicast address resolution (MARS)

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...NAME=1152> FIFO

FIFO=First In First Out

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...promiscuous

promiscuous mode is when ``all'' addresses are listened to at the same time

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...MARS

Actually this is done only for the first transmission or when the server has lost track of the coming and going of group memberships. For the purpose of the discussion, the MARP procedure is discussed anyway.

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...knows

See also Chapter 3, the multicast routing protocols like DVMRP, are not discussed in this thesis.

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...(GPL)

The GPL can be characterized by the following sentence: ``This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.''
A Web Location for the GPL: http://www.fsf.org/copyleft/copyleft.html

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...daemons

Daemons are server applications that stay resident

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...up-to-date

The information is not always correct, complete or specific enough, the semi-support for point-to-multipoint VCCs is an example of this.

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...VCCs

This statement is too strict, see Section 6.2.2

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...signalling

Werner Almesberger, the coordinator of the Linux-ATM project, is working on this

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...Supposedly

This information is not documented anywhere and no authoritative confirmations of this (by Werner Almesberger) exist at this time. However, several people (Marko Kiiskilä (carnil@alpha.cc.tut.fi) and Ricardo Sanchez (rsanchez@ittc.ukans.edu), at least) have said the same thing.

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...VCC

In fact, the section about pt-mpt signalling refers to the point-to-point specification in [UNI31, Section 5.5,] for the first SETUP message.

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...ago

This was written on June 26th, 1997

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...IDT

Information about IDT network adapters can be found at URL: http://www.idt.com/cgi-bin/psq.pl?mkgkey=atm

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...HREF="node10.html#linuxatmstack">6.3

This figure is adapted from a figure used by Werner Almesberger in a presentation about Linux-ATM. [WA96]

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...``table''

[linux/net/atm/atmarp.c:clip_xmit()]

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...multicasting

ATMARP could well be interpreted as ATM Address Resolution Protocol, including multicasting, so the choice of this module is not too strange. The problem is that it could confuse matters, because ATMARP is generally associated with Classical IP and ARP over ATM.

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...router

This does not necessarily have to be the unicast IP router

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...software

Do not underestimate the delays that can be caused by slow deliverance of commercial products!

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...(2.2.x)

Linux kernel numberings should be interpreted as follows: the first number is not special and seldom updated. The second number, when odd, signifies a development version of the next even numbered feature upgrade. The third number, in an even middle numbered kernel, signifies a bug-fix release or a small driver addition. In a development kernel, the third number is just a version counter and usually features are added with each update.

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...probably

This is an estimation of the time, inferred from discussions with colleagues with more Linux experience than the author.

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...2022

Support for Multicast over UNI 3.0/3.1 based ATM Networks

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...2149

Multicast Server Architectures for MARS-based ATM multicasting

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...anycast

choose the closest of a group of destinations, addresses with one anycast address

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...future

In the next 10 to 15 years from the time of this writing.

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...1990

In 1997 a second edition will be published in three volumes

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