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3 Quality of service ( QOS) and network performance ( NP)

3 Quality of service ( QOS) and network performance ( NP)

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Network management

613

exception. The traffic volumes continue to grow exponentially, and the bit rates of the user
connection lines and services become ever faster.
Experience with other data network technologies and protocols suggest that the protocols
and bit rates today used in the ‘core’ of a network, will tomorrow be migrated to the ‘edge’
(i.e., periphery) of the network and be replaced in the ‘core’ by new protocols, using even
higher bit rates and faster transmission technologies. Thus, for example, the 100 Mbit/s fast
ethernet interfaces used five years ago mainly in the backbones of large campus LANs (local
area networks) are now commonly used as user-network interfaces (UNI) for connecting hosts
and other end devices. The backbone meanwhile has migrated to the 1000 Mbit/s speed of
Gigabit ethernet. But now, the price of Gigabit ethernet interfaces is dropping to a level,
where it too can be considered for wider use as a user-network interface (UNI). The backbone
will now have to migrate to even higher bit rates, to cope with the extra traffic volume that
will result.
With each order-of-magnitude leap in the bit rate required, the technologies and protocols
of the network backbone are severely challenged. Just because a protocol was ideally suited
to a lower backbone bit rate is not any guarantee that it will work at all at a much higher bit
rate! The technical, physical, electrical, optical and processing limits of network components
may demand a major change in the basic operation of a protocol or even make it unviable, so
requiring its replacement with a new protocol better suited to the higher bit rate.
While there is no declared upper limit (bit rate or otherwise) of the capabilities of IPv6
(Internet protocol version 6), there are bound to be constraints which will become apparent
over time. The future is thus likely to bring Internet protocol versions 7, 8, 9 and so on — but
other than the fact that they share the name ‘IP’, they may have little in common, and may
be fully incompatible, with today’s versions IPv4 and IPv6! Already, IPv4 and IPv6 need to
be treated as different, albeit interworkable protocols.
The current trend in IP-backbone networks is for the use of MPLS (multiprotocol label
switching) and IPv6 (Internet protocol version 6) protocols at the ‘core’ of the network. These
protocols have been developed to be better suited to higher bit rates and the assurance of
network quality of service (QOS), thus making them better suited than IPv4 for the handling
of real-time traffic such as video and voice-over-IP (VOIP).

15.5 Network management
An unfortunate, but inevitable reality, is that the tools available for managing telecommunications networks are always somewhat behind the capabilities of the networks themselves. The
tools tend to be developed to control individual elements of the network, rather than for the
optimisation and control of the network as a whole. While the range and capabilities of network management tools for complete service and network management continue to increase,
there is always bound to be a role for the human network specialist!!

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Appendix 1
Protocol Addresses, Port
Numbers, Service Access Point
Identifiers (SAPIs) and
Common Presentation Formats

This appendix presents for easy reference the most commonly used service access point identifiers (SAPIs), protocol addresses, protocol numbers and port numbers as used by protocol
layers 1–4 to identify the hardware address, network address or nature of the next higher protocol. In addition, it presents common presentation formats, including the ASCII code (7-bit),
extended ASCII (8-bit) and NVT-ASCII as well as MIME-media types.
As a general point of enquiry for the most up-to-data protocol and port number assignments,
you may wish to refer also to the following website address:
www.iana.org/numbers.html

Layer 1 (physical layer): LAN MAC addresses
(hardware addresses)
The MAC (medium access control) used in LANs (local area networks) uses a 48-bit IEEE
unique identifier (also called the MAC address or hardware address). The first three bytes
of the address (most significant bit values) comprise the organisation unique identifier (OUI)
of the equipment or network interface card (NIC) manufacturer (Table A1.1). The last three
bytes are a number unique to each individual piece of hardware. This value is ‘burned into’
the equipment at its time of manufacture. Values appear in the source and destination MACaddress fields of the MAC-header. Alternatively, a multicast address may be in use as the
MAC-address (Table A1.2).
The most current list of organisation unique identifiers (OUIs) can be viewed on the IEEE
website at:
http://standards.ieee.org/regauth/oui/index.shtml

Data Networks, IP and the Internet: Protocols, Design and Operation
 2003 John Wiley & Sons, Ltd ISBN: 0-470-84856-1

Martin P. Clark

616
Table A1.1

Appendix 1 Protocol addresses, port numbers and (SAPIs)
IEEE unique identifiers (48-bit) used in the MAC-address field: well known examples of
the organisation unique identifier (OUI)

Organization

Organisational unique identifier (OUI)
value in hexadecimal (3 bytes total)

Apple computer
Cisco
Compaq (ex-Digital)
Hewlett Packard (HP)
IANA (Internet Assigned Numbers Authority)
IANA multicast (RFC 1054)
IBM
Novell

08-00-07
00-00-0C
08-00-2B and 00-00-F8
08-00-09
00-00-5E
01-00-5E
10-00-5A
00-00-1B

LAN multicast addresses
Table A1.2 LAN-MAC (medium access control) multicast addresses
Multicast address
01-80-C2-00-00-00
01-80-C2-00-00-10
01-00-5E-00-00-01 (224.0.0.1)
01-00-5E-00-00-02 (224.0.0.2)
01-00-5E-00-00-05 (224.0.0.5)
01-00-5E-00-00-06 (224.0.0.6)
01-00-5E-00-00-09 (224.0.0.9)
01-00-5E-00-00-0A (224.0.0.10)
01-00-5E-00-00-0D (224.0.0.13)
01-00-5E-00-01-18 (224.0.1.24)
01-00-5E-00-01-27 (224.0.1.39)
01-00-5E-00-01-28 (224.0.1.40)
01-00-5E-00-01-29 (224.0.1.41)
01-00-5E-00-01-4B (224.0.1.75)
01-00-5E-02-7F-FE (224.2.127.254)
30-00-00-00-00-01

Meaning
IEEE 802.1d protocol
IEEE 802.1d All− Bridge− Management
All systems on this (IP) subnet
All routers on this (IP) subnet
All OSPF (open shortest path first) routers
All designated OSPF (open shortest path first) routers
RIPv2 (routing information protocol) routers
IGRP (Cisco interior gateway routing protocol) routers
All PIM (protocol independent multicast) routers
Microsoft WINS server autodiscovery
Cisco PIM rendezvous point announcements
Cisco PIM rendezvous point discovery
ITU-T H.225 gatekeeper discovery
SIP (session initiation protocol) ALL− SIP− Server
SAP (session announcement protocol) announcements
NetBEUI multicast

Layer 2 (datalink layer): HDLC, LLC and PPP protocol types
HDLC (higher level datalink control)
The HDLC address field comprises an 8-bit value. On a point-to-point link, only two values are
assigned — one to represent the DCE (data circuit terminating equipment) and one to represent
the DTE (data terminal equipment). There are two reserved addresses. These are the values
1111 1111 (all stations broadcast) and 0000 0000 (no stations)

LLC (logical link control) — datalink protocol used in LANs
In the LLC protocol, the service access point identifier (SAPI) in the SAP address (protocol)
field indicates how the contents of the data frame are to be handled — according to Table A1.3.

Layer 2 (datalink layer): HDLC, LLC and PPP protocol types
Table A1.3

617

Logical link control (LLC) service access point identifiers (SAPIs)

Service access point (SAP)
identifier (SAPI)
04, 08, 0C (05, 09, 0D as group identifiers)
0A
42
AA
7E
FE
F0 (F1 as group identifier)
E0 (E1 as group identifier)

Protocol and address
format in use
SNA (systems network architecture)
IEEE 802.10 standard for interoperable
LAN/MAN security (SILS)
IEEE 802.1d transparent bridging
IEEE 802.2 SNAP (subnetwork address protocol)
X.25 over ethernet (ISO 8208)
ISO network layer protocol
NetBEUI
Novell

Table A1.4 Protocol types supported by ethernet SNAP-format (EtherType field)
Protocol

Protocol type (PT) value in
hexadecimal (2 bytes total)

Address resolution protocol (ARP)
Appletalk
Appletalk ARP (address resolution protocol)
DECnet maintenance operations protocol (MOP)
DECnet local area transport (LAT) protocol
DECnet routing
IBM SNA over ethernet
IEEE 802.1Q (VLANs, virtual LANs)
Internet protocol version 4 (IP v4)
Internet protocol version 6 (IP v6)
Novell IPX (Internetwork packet exchange) protocol
Reverse address resolution protocol (RARP)
Simple network management protocol (SNMP)
Xerox network system (XNS)

08-06
80-9B
80-F3
60-01
60-04
60-03
80-D5
81-00
08-00
86-DD
81-37
80-35
81-4C
06-00

The most common values used are the values 1111 1111 (all stations broadcast), 0000 0000
(no stations) or the value ‘AA’ (indicating the use of the SNAP — subnetwork address protocol )
(as illustrated in Chapter 4–Figure 4.6).
When both the source-SAP (service access point) and destination-SAP fields of the LLC
header are set to value ‘AA’ (10101010), then the SNAP (subnetwork address protocol) format
is in use. In this format a PT (protocol type field) is included, which indicates the protocol
being used at the next higher layer, e.g., as a network protocol (see Table A1.4).
The most current list of protocol types (EtherType field values) can be viewed on the IEEE
website at:
http://standards.ieee.org/regauth/ethertype/type-pub.html

PPP protocol assignments
Table A1.5 lists the coding of the PPP protocol type field. This reveals the protocol in use
(e.g., Internet protocol) for coding the user data held as the contents of the PPP packet.

618

Appendix 1 Protocol addresses, port numbers and (SAPIs)
Table A1.5

PPP protocol value field — common values

Protocol type

Protocol
value range

Allocated value

Network layer
protocols

0xxx — 3xxx 0001

Protocol
Padding protocol

0003

Robust Header Compression (ROHC small-CID,
context identifier: RFC 3095)
0005
Robust Header Compression (ROHC large-CID,
context identifier: RFC 3095)
0007 — to — 001F Reserved (transparency efficient)
0021
Internet Protocol v4
0023
OSI network layer
002B
Novell IPX
002D
Van Jacobsen compressed TCP/IP (RFC 2508)
002F
Van Jacobsen uncompressed TCP/IP (RFC 2508)
0031
Bridging PDU
003D
PPP Multilink protocol (MP — RFC 1717)
003F
NetBIOS framing
0041
Cisco systems
0049
Serial data transport protocol (SDTP — RFC
1963)
004B
IBM SNA over IEEE 802.2
004D
IBM SNA
0057
Internet Protocol v6
0059
PPP muxing (RFC 3153)
0061–0069
RTP (Real-Time Transport Protocol) Internet
Protocol Header Compression (IPHC — RFC
2509)
007D
Reserved (control escape — RFC 1661)
007F
Reserved (compression inefficient — RFC 1662)
00CF
Reserved (PPP NLPID)
00FB
Single link compression in multilink (RFC 1962)
00FD
Compressed datagram (RFC 1962)
00FF
Reserved (compression inefficient)
IEEE 802.1p hello protocol
02xx — 1Exx 0201
IBM source routing BPDU
(compres- 0203
Cisco discovery protocol
0207
sion
MPLS unicast
inefficient) 0281
MPLS multicast
0283
Real-time Transport Protocol (RTP) Internet
2063–2069
Protocol
Header Compression (IPHC — RFC 2509)
4xxx — 7xxx See www.iana.org

Low volume
traffic
protocols
with no NCP
Network control 8xxx — Bxxx 8001–801F
protocols
(NCPs)
8021
8023
802B
802D
802F
8031

Unused

IPv4 control protocol (RFC 1332)
OSI network layer control protocol (RFC 1377)
Novell IPX control protocol (RFC 1552)
Reserved
Reserved
Bridging control protocol (BCP — RFC 2878)

Layer 3 (network layer): Internet addresses and protocol numbers
Table A1.5

(continued )

Protocol type

Protocol
value range

Allocated value
803D
803F
8041
8049
804B
804D
8057
8059
807D
80CF
80FB

Link control
protocols
(LCPs)

619

80FD
80FF
Cxxx — Fxxx C021

C023
C025
C029
C02B
C02D
C223
C227

Protocol
Multilink control protocol (RFC 1717)
NetBIOS framing control protocol (RFC 2097)
Cisco systems control protocol
Serial data control protocol (SDCP)
IBM SNA over IEEE 802.2 control protocol
IBM SNA control protocol (RFC 2043)
IPv6 control protocol
PPP muxing control protocol (RFC 3153)
Unused (RFC 1661)
Unused (RFC 1661)
Single link compression in multilink control (RFC
1962)
Compression control protocol (CCP — RFC 1962)
Unused (RFC 1661)
Link control protocol (LCP)

Password authentication protocol (PAP — RFC
1334)
Link quality report
CallBack control protocol (CBCP)
Bandwidth allocation control protocol
(BACP — RFC 2125)
Bandwidth allocation protocol (BAP — RFC
2125)
Challenge handshake authentication protocol
(CHAP — RFC 1994)
Extensible authentication protocol (RFC 2284)

The most current list of protocol types (PPP protocol numbers) can be viewed on the IANA
website at:
www.iana.org/assignments/ppp-numbers

Layer 3 (network layer): Internet addresses and protocol numbers
The Internet protocol uses both address format fields (source and destination network address)
as well as a protocol type field (called next header field in IPv6).

Network address (IP address)
IPv4 address field
Addresses of IPv4 (Internet protocol version 4) format are 32-bit values, usually denoted as a
series of decimal values separated by ‘dots’ thus:
d1.d2.d3.d4

where each value d1-d4 takes a numerical integer value between 0 and 255. The values
d1 correspond to class A address-ranges. These ranges are assigned by IANA (Internet

620

Appendix 1 Protocol addresses, port numbers and (SAPIs)

Assigned Numbers Authority) and delegated registration authorities. Current allocations appear
in Table A1.6.
The most current list of IPv4 address assignments can be viewed on the IANA website at:
www.iana.org/assignments/ipv4-address-space

IPv6 address field
Addresses of IPv6 (Internet protocol version 6) format are 128-bit values, usually denoted as
a series of hexadecimal values separated by ‘colons’ thus:
hhhh:hhhh:hhhh:hhhh:hhhh:hhhh:hhhh:hhhh

where each value individual hexadecimal value h takes a value between 0 and A. The various different ranges of IPv6 addresses are assigned by IANA (Internet Assigned Numbers
Authority) and delegated registration authorities. Current allocations appear in Table A1.7.
The most current list of IPv6 address assignments can be viewed on the IANA website at:
www.iana.org/assignments/ipv6-address-space

Table A1.6

Allocation of IPv4 class A address ranges

Decimal value (first
8 bits of IPv4 address)

Assignment

0–2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29–30
31
32

IANA — reserved
General Electric Company
BBN (Bolt, Beranek and Newman)
IANA — reserved
US Army information systems center
IANA — reserved
BBN (Bolt, Beranek and Newman)
IBM
IANA — reserved for private IP addresses
US Department of Defense (DoD) Intel information services
AT&T Bell Laboratories
Xerox Corporation
IANA — public data network
Hewlett Packard
Digital Equipment Corporation (now COMPAQ/HP)
Apple Computer Inc
MIT (Massachusetts Institute of Technology)
Ford Motor Company
CSC (Computer Sciences Corporation)
DDN-RVN
US Defense information services agency
IANA — reserved
ARIN (American Registry for Internet Numbers)
UK Royal Signals and Radar Establishment
US Defense information services agency
IANA — reserved
DSI — north
US Defense information services agency
IANA — reserved
Norsk Informasjonsteknologi

Layer 3 (network layer): Internet addresses and protocol numbers
Table A1.6

(continued )

Decimal value (first
8 bits of IPv4 address)
33
34
35
36
37
38
39
40
41–42
43
44
45
46
47
48
49–50
51
52
53
54
55
56
57
58–60
61
62
63–68
69–79
80–81
82–128
129–191
192
193–195
196
197
198
199–200
201
202–203
204–209
210–211
212–213
214–215
216
217
218–220
221–223
224–239
240–255

Assignment
DLA system automation center
Halliburton Company
MERIT computer network
IANA — reserved (formerly Stanford University)
IANA — reserved
PSI (performance systems international)
IANA — reserved
Eli Lilly and Company
IANA — reserved
Japan Inet
Amateur Radio Digital Communications
Interop Show network
BBN (Bolt, Beranek and Newman)
Bell-Northern Research
Prudential Securities
IANA (formerly Joint Technical Command)
UK (Department of Social Security — DSS)
E.I. duPont de Nemours and Co., Inc
Cap Debis CCS
Merck and Co. Inc
Boeing Computer Services
US Postal Service
SITA (Soci´et´e Internationale de T´el´ecommunications
A´eronautiques)
IANA — reserved
APNIC (Asia-Pacific Network Information Centre)
RIPE (R´eseaux IP Europ´eens)
ARIN (American Registry for Internet Numbers)
IANA — reserved
RIPE (R´eseaux IP Europ´eens)
IANA — reserved
Various registries
Various registries, multiregional
RIPE (R´eseaux IP Europ´eens)
Various registries
IANA — reserved
Various registries
ARIN (American Registry for Internet Numbers)
Central and South America
APNIC (Asia-Pacific Network Information Centre)
ARIN (American Registry for Internet Numbers)
APNIC (Asia-Pacific Network Information Centre)
RIPE (R´eseaux IP Europ´eens)
US Department of Defense (DoD)
ARIN (American Registry for Internet Numbers)
RIPE (R´eseaux IP Europ´eens)
APNIC (Asia-Pacific Network Information Centre)
IANA — reserved
IANA — multicast (see also Table A1.4)
IANA — reserved

621

622

Appendix 1 Protocol addresses, port numbers and (SAPIs)
Table A1.7
IPv6 prefix
0000
0000
0000
0001
1111
1111
1111

0000
001
010
1110 10
1110 11
1111

IPv6 address range allocations
Usage
Reserved
Network Service Access Point (NSAP)
IPX
Global unicast addresses (RFC 2374)
Link-local unicast addresses
Site-local unicast addresses
Multicast addresses

Protocol type
The protocol type field of the IPv4 header and the next header field of the IPv6 header reveal
the protocol used to code the data held in the IP packet payload. Common protocol values are
listed in Table A1.8. The most current list of protocol number assignments can be viewed on
the IANA website at:
www.iana.org/assignments/protocol-numbers

Table A1.8

Protocol field values (IANA protocol numbers) and their meanings

Protocol field value
(possible range 0–255)
0
1
2
4
6
7
8
9
10
27
28
30
35
42
43
44
45
46
47
48
50
51
54
58
59
60

Protocol used at next higher layer
(i.e., content type of IP-data field)
HOPOPT — IPv6 Hop-by-Hop Option
ICMP — Internet Control Message Protocol
ˆIGMP — Internet Group Management Protocol
ˆIP in IP encapsulation (RFC 2003)
TCP — Transmission Control Protocol
CBT — Core-Based Trees
EGP — Exterior Gateway Protocol
IGP — Interior Gateway Protocol (e.g., Cisco’s
IGRP)
UDP — User Datagram Protocol
RDP — Reliable Data Protocol
IRTP — Internet Reliable Transaction Protocol
NETBLT — Bulk Transfer Data Protocol
IDPR — Inter-Domain Policy Routing Protocol
SDRP — Source Demand Routing Protocol
IPv6-Route — Routing Header for IPv6
IPv6-Frag — IPv6 Fragment header follows
IDRP — Inter-Domain Routing Protocol
RSVP — Resource ReSerVation Protocol
GRE — Generic Routing Encapsulation
MHRP — Mobile Host Routing Protocol
ESP — Encapsulation Security Payload for IPv6
AH — Authentication Header for IPv6
NARP — NBMA Address Resolution Protocol
IPv6-ICMP — ICMP for IPv6
IPv6-NoNxt — No next header — payload should be
ignored
IPv6-Opts — Destination Options for IPv6

Layer 4 (transport layer): port numbers
Table A1.8

623

(continued )

Protocol field value
(possible range 0–255)

Protocol used at next higher layer
(i.e., content type of IP-data field)

80
81
88

ISO-IP — ISO Internet Protocol
VMTP — Versatile Message Transaction Protocol
EIGRP — Extended Interior Gateway Routing
Protocol (Cisco)
OSPF — Open Shortest Path First
MTP — Multicast Transport Protocol
MICP — Mobile Interworking Control Protocol
ETHERIP — Ethernet-within-IP encapsulation
ENCAP — Encapsulation header / private encryption
PIM — Protocol Independent Multicast
IP Comp — IP Payload Compression Protocol
Novell IPX-in-IP
VRRP — Virtual Router Redundancy Protocol
L2TP — Layer 2 Tunneling Protocol

89
92
95
97
98
103
108
111
112
115

Layer 4 (transport layer): port numbers
The service access point identifiers (SAPIs) used at the transport layer by the transmission
control protocol (TCP) and the user datagram protocol (UDP) are called port numbers or socket
numbers Port numbers are 16-bit binary values (decimal: 0–65 535) which are assigned by
IANA according to the following broad scheme:
• well-known ports 0–1023
• registered ports 1024–49151
• dynamic and private ports 49152–65535
Commonly used port number values are listed in Table A1.9.
Table A1.9

TCP (transmission control protocol) and UDP (user datagram protocol) port numbers

TCP or
UDP / TCP
UDP as
port
carriage protocol
number
21
22

TCP
TCP

23
25
53
65

TCP
TCP
TCP/UDP
TCP/UDP

67

UDP

68

UDP

69

UDP

Application protocol or service

FTP (file transfer protocol)
SSH (secure shell) remote login protocol and secure forwarding
protocol
Telnet
SMTP (simple mail transfer protocol)
DNS (domain names service)
TACACS (terminal access controller access control system) database
service
BOOTP (bootstrap protocol) / DHCP (dynamic host configuration
protocol) server
BOOTP (bootstrap protocol) / DHCP (dynamic host configuration
protocol) client
TFTP (trivial file transfer protocol)
(continued overleaf )