CompTIA Network+ Certification Study Guide part 67 pdf

Appendix A
646

Table A.1
Listing of 802 IEEE Standards continued
Standard Subject\Description
802.6j Standard for Connection Oriented Services on a Distributed Queue Dual Bus
Subnetwork of a Metropolitan Area Network
802.6k Distributed Queue Dual Subnetwork of a MAN. Supplement for MAC bridging
802.6l Point-to-Point Interface for Subnetwork of MAN. Specification for network
between two locations in a MAN
802.6m Subnetwork of MAN
802.7 Recommended Practices for Broadband LAN. Provides recommendations for
the physical, electrical, and mechanical practices of broadband coaxial media
802.8 Fiber Optic Technical Advisory Group LAN. Standard for fiber optic technology
802.9 Integrated Services (IS) LAN Interface at the MAC and Physical Layer. Standard
for voice and data over twisted-pair media
802.9a Supplement to Integrated Services LAN: IEEE 802.9 Isochronous Service
with CSMA/CD MAC Service
802.9b Supplement for Functional Specification for AU to AU Interworking IEEE 802.9
802.9c Supplement to 802.9, Management Object Conformance Statement
802.9d Supplement to 802.9, PICS
802.10 Standard for Interoperable LAN Security (SILS). Standard for allowing secure
LAN products to interoperate using encryption
802.10a SILS Part A: The Model
802.10b SILS Part B: Secure Data Exchange. Standard on protocol for secure data
exchange at Data Link Layer
802.10c SILS Part C: Key Management. Standard on the management and distribution
of cryptography keys
802.10d SILS Part D: Security Management
802.10e LAN: Recommended Practice of Secure Data Exchange on Ethernet 2.0.

Specifies secure data exchange on LANs using Ethernet
802.10f Secure Data Exchange: Sublayer
802.10g Standard for Security Labeling Within Secure Data Exchange
802.10h Supplement to Interoperable LM Security: PICS Proforma/Security Data
802.11 Standard for WLAN. Standard for MAC and physical layer for wireless
networking
802.12 Demand Priority Access Method, Physical and Repeater Specifications,
100 Mb/s. Standard dealing with 100 Mbs LANs
802.14 Standard Protocol for Cable-TV Based Broadband Communication Network.
Standard for cable modems
802.15 WPAN
802.16 Broadband Wireless Access
Appendix A 647
Table A.1
Listing of 802 IEEE Standards continued
Standard Subject\Description
802.17 Resilient Packet Ring
802.18 Radio Regulatory
802.19 Coexistence
802.20 MBWA
802.21 Media Independent Handoff
802.22 Wireless Regional Area Networks
1802.3-
1991
IEEE Supplement to IEEE Std 802-1990: Methodology and Implementation
for Attachment Unit Interface (AUI) Cable Conformance Testing
1802.3a Supplement to CSMA/CD Access Method and Physical Layer Specifications:
Methodology and Implementation for MAC Conformance Testing
1802.3b Supplement to CSMA/CD Access Method and Physical Layer Specifications:
Methodology and Implementation for PLS, Type 10, Conformance Testing

1802.3c Supplement to CSMA/CD Access Method and Physical Layer Specifications:
Methodology and Implementation for MAU, Type 10BASE-5, Conformance
Testing
1802.3d Conformance Test Methodology for IEEE Standards for LAN and MAN
Networks: CSMA/CD Access Method and Physical Layer Specifications Type
10BASE-T
While there are numerous IEEE standards that have been developed for
networking, the Network+ exam only expects you to know the basic funda-
mentals of a select few. The standards that will be referenced in the exam
and that we’ll discuss in this appendix, are:
802.2 LLC
802.3 CSMA\CD
802.5 Token Ring
802.11 Wireless
802.2 LLC
Earlier in this chapter, we explained how 802 standards break the Data Link
Layer of the OSI model into two sublayers: the MAC and the LLC. The LLC
is used to establish connections between computers, and is used by other
protocols defined by the 802 committee.
When the LLC receives data in the form of a “frame” from the layer
above it (the Network Layer), it breaks it apart into smaller pieces that can
Appendix A
648
be sent over network media. It also adds header information that identifies
upper layer protocols sending the frame, and can also specify destination
processes for the data. The computer receiving the data will view this header
information, and use it to reassemble the data into its proper format.
802.3 CSMA/CD
On the basis of the original Ethernet network from Digital- Intel-Xerox
(DIX), 802.3 is the standard for Ethernet networks today. The only difference

between 802.3 Ethernet and DIX Ethernet V.2 is the frame type. The two
Ethernet networks can use the same physical network, but devices on one
standard cannot communicate with devices on the other standard.
The MAC sublayer uses CSMA/CD for access to the physical medium.
CSMA/CD keeps devices on the network from interfering with one another
when trying to transmit; if they do, a collision occurs. To reduce collisions,
CSMA/CD devices listen to the network before transmitting. If the network
is “quiet” (no other devices are transmitting), the device can send data. Since
two devices can think that the network is clear and start transmitting at the
same time, resulting in a collision, all devices listen as they transmit. If a
device detects another device is transmitting at the same time, a collision
occurs. The device stops transmitting and sends a signal to alert other
nodes about the collision. Then, all the nodes stop transmitting and wait a
random amount of time before they begin the process again.
CSMA/CD doesn’t stop collisions from happening, but it helps manage
the situation when they do occur. In fact, collisions are a normal part of
Ethernet operation. It’s only when collisions begin to occur frequently that
you needed to become concerned.
Ethernet has evolved over the years to include a number of popular spec-
ifications. These specifications are due in part to the media variety they
employ, such as coaxial, twisted-pair, and fiber-optic cabling.
The 10Base5 specification, commonly referred to as  Thicknet, was the
original Ethernet specification and has a maximum distance of 500 m
(approximately 1640 feet) with a speed of 2.94 to 10 Mbps.
The 10Base2 specification, commonly referred to as  Thinnet, uses
a thinner coaxial cable than 10Base5 does and has a maximum
distance of 185 m (approximately 607 feet) with a maximum speed
of 10 Mbps.
The 10BaseT specification uses twisted-pair cabling with a maxi-


mum distance of 100 m (approximately 328 feet) with a speed of 10
to 100 Mbps.
Appendix A 649
802.5 Token Ring
Although Token Ring was first designed in the 1960s, IBM’s token passing
implementation did not become a standard until 1985. The 802.5 standard
was modeled after the IBM Token Ring network, which had been in use for
many years before the standard was developed.
The 802.5 network introduced a unique access method: token passing.
The Token Ring IEEE 802.5 standard passes a special frame known as a
token around the network. This token is generated by the first computer
that comes online on the Token Ring network. When a workstation wants
to transmit data, it grabs the token and then begins transmitting. This
computer will send a data frame on the network with the address of the
destination computer. The destination computer receives the data frame,
modifies it, and sends it onto the network back to the original computer,
indicating successful transmission of data. When the workstation is finished
transmitting, the token is released back onto the network. This ensures
that workstations will not simultaneously communicate on the network, as
in the CSMA/CD method.
802.11 Wireless
The IEEE 802.11 standard addresses wireless networking. This standard
includes the Wireless Access Point (WAP) devices and the wireless network
interface cards (NICs) that are used to send and receive broadcasts from the
cell or WAP device.
The WAPs and wireless NICs can be set to use different frequencies to
allow for cell overlap. This technology does not include the same technology
used by cell phones to manage the movement of PCs or mobile devices. The
wireless NIC is set to a specific frequency and must be changed manually to
be able to communicate with another cell. This means that a PC cannot be

moved from one cell area to another without changing frequency, unless for
some reason the cells operate on the same frequency and have no overlap
of coverage area.
Exam Warning
IEEE standards are an important part of networking, and chances are that you’ll see
questions on them during the exam. You’ll be tested on the main features of LLC, CSMA\
CD (Ethernet), Token Ring, and Wireless technologies. Because Token Ring and Wireless
technologies are also part of the topologies we covered earlier in this chapter, you should
review these topologies to have a firm understanding of the standards. Make sure you
are aware of the basics of 802.2, 802.3, 802.5, and 802.11.
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651
Appendix B
UNDERSTANDING REQUEST FOR COMMENTS
Request for Comments
Request for Comments (RFCs) are documents describing a particular idea,
method, technology innovation or other concept that relates to Internet-
connected systems. These documents are posted and presented to technical
communities as RFCs, and move through different classifications such as
informational or experimental. Some end up on the standards track and
begin the journey as proposed standards. While some RFCs go on to become
standards, others do not. RFCs began in 1969 when the Internet was still
in its incarnation as the Advanced Research Projects Agency Network
(ARPANet). While not all of the RFC specifically deal with the Internet,
all of the Internet standards are written as RFC. They focus on networking
protocols, communication issues, procedures, concepts, and other topics.
RFC are created and maintained by the Internet Engineering Task Force
(IETF). The IETF is an organization that consists of vendors, network admin-
istrators, designers, researchers, and other professionals who are interested
in the operation and future of the Internet. These people can provide pro-

posals to the IETF, which in turn provides a consensus on new standards
that should be added. The proposals that are submitted are called “Internet
Drafts,” which are reviewed by working groups that specialize in specific
areas. If a standard is developed as a result of the Internet Draft, it is written
as an RFC and categorized as a standard.
Using RFC
RFC are categorized using a number that is preceded by the prefix “RFC”.
For example, the RFC dealing with the Domain Name System is RFC 1034.
In reading a Request for Comment, you will find that there is a section that
shows the category or status of the document. These categories include:
Standards-track Documents – have the status of being a Standard,

Draft Standard, and Proposed Standard. This shows its current
state in becoming a standard
Appendix B
652
Best Current Practice – provides procedures and recommendations
Informational – provides information on various subjects. This 
category also includes the IETF’s joke RFC, such as RFC1217
(Memo from the Consortium for Slow Commotion Research
[CSCR]), and RFC1438 (Statements of Boredom [SOBs])
Experimental – designates a particular practice or topic as 
experimental in nature
Historic – standards that are no longer used.
Because the IETF doesn’t remove RFC, all of them are still available for
viewing. Ones that aren’t used are listed as being historic documents, but are
still available for reference purposes. This provides those using the RFC with
the ability to review practices, principles, and protocols that are no longer in
use, but that can be valuable if previous standards need to be reviewed.
As is the case with the Institute of Electrical and Electronics Engineers

(IEEE) standards, the number of standards published by the IETF is massive.
Rather than providing all of them here, Table B.1 provides a list of the Inter-
net standards, many of which also relate to intranets and networks using
Transmission Control Protocol/Internet Protocol (TCP/IP).
Table B.1
IETF Internet Related Standards
RFC Subject\Description
RFC768 User Datagram Protocol
RFC791 Internet Protocol
RFC792 Internet Control Message Protocol
RFC793 Transmission Control Protocol
RFC821 Simple Mail Transfer Protocol
RFC822 Standard for the format of ARPA Internet text messages
Test Day Tip
The IETF’s RFC can easily be distinguished from IEEE standards by their title. IEEE
standards dealing with LANs begin with 802, while RFC begin with RFC.
RFC aren’t extensively covered in the exam, but they can still prove interesting and
useful to review, and provide an additional source of information. A full listing of RFC
can be found at www.ietf.org/iesg/1rfc_index.txt, or by using the RFC online database at
www.rfc-editor.org/rfc.html.
Appendix B 653
Table B.1
IETF Internet Related Standards continued
RFC Subject\Description
RFC826 Ethernet Address Resolution Protocol: Or converting network protocol
addresses to 48-bit Ethernet address for transmission on Ethernet hardware
RFC854 Telnet Protocol Specification
RFC855 Telnet Option Specifications
RFC856 Telnet Binary Transmission
RFC857 Telnet Echo Option

RFC858 Telnet Suppress Go Ahead Option
RFC859 Telnet Status Option
RFC860 Telnet Timing Mark Option
RFC861 Telnet Extended Options: List Option
RFC862 Echo Protocol
RFC863 Discard Protocol
RFC864 Character Generator Protocol
RFC865 Quote of the Day Protocol
RFC866 Active Users
RFC867 Daytime Protocol
RFC868 Time Protocol
RFC891 Distributed Computer Network local-network protocols
RFC894 Standard for the transmission of IP datagrams over Ethernet networks
RFC895 Standard for the transmission of IP datagrams over experimental Ethernet
networks
RFC903 Reverse Address Resolution Protocol
RFC907 Host Access Protocol specification
RFC919 Broadcasting Internet datagrams
RFC922 Broadcasting Internet datagrams in the presence of subnets
RFC950 Internet Standard Subnetting Procedure
RFC959 File Transfer Protocol
RFC1001 Protocol standard for a Network Basic Input/Output System (NetBIOS)
service on a Transmission Control Protocol/User Datagram Protocol (TCP/
UDP) transport: Concepts and methods
RFC1002 Protocol standard for a NetBIOS service on a TCP/UDP transport: Detailed
specifications
RFC1006 ISO transport services on top of the TCP: Version 3
RFC1034 Domain names – concepts and facilities
Continued
Appendix B

654
Table B.1
IETF Internet Related Standards continued
RFC Subject\Description
RFC1035 Domain names – implementation and specification
RFC1042 Standard for the transmission of IP datagrams over IEEE 802 networks
RFC1044 Internet Protocol on Network System’s HYPERchannel: Protocol specification
RFC1055 Nonstandard for transmission of IP datagrams over serial lines: SLIP
RFC1088 Standard for the transmission of IP datagrams over NetBIOS networks
RFC1112 Host extensions for IP multicasting
RFC1122 Requirements for Internet Hosts – Communication Layers
RFC1123 Requirements for Internet Hosts – Application and Support
RFC1132 Standard for the transmission of 802.2 packets over Internetwork Packet
Exchange networks
RFC1155 Structure and identification of management information for TCP/IP-based
internets
RFC1201 Transmitting IP traffic over Attached Resource Computer networks
RFC1209 Transmission of IP datagrams over the Switched Multi-megabit Data Service
RFC1212 Concise Management Information Base (MIB) definitions
RFC1213 MIB for Network Management of TCP/IP-based internets: MIB-II
RFC1350 The Trivial File Transfer Protocol (Revision 2)
RFC1390 Transmission of IP and ARP over Fiber Distributed Data Interface Networks
RFC1661 The Point-to-Point Protocol (PPP)
RFC1662 PPP in High Level Data Link Control–like Framing
RFC1722 Routing Information Protocol (RIP) Version 2 Protocol Applicability Statement
RFC1870 Simple Mail Transfer Protocol (SMTP) Service Extension for Message Size
Declaration
RFC1939 Post Office Protocol – Version 3
RFC2289 A One-Time Password System
RFC2328 Open Shortest Path First Version 2

RFC2427 Multiprotocol Interconnect over Frame Relay
RFC2453 RIP Version 2
RFC2578 Structure of Management Information Version 2 (SMIv2)
RFC2579 Textual Conventions for SMIv2
RFC2580 Conformance Statements for SMIv2
RFC2819 Remote Network Monitoring MIB
RFC2920 SMTP Service Extension for Command Pipelining
Appendix B 655
Table B.1
IETF Internet Related Standards continued
RFC Subject\Description
RFC3411 An Architecture for Describing Simple Network Management Protocol
(SNMP) Management Frameworks
RFC3412 Message Processing and Dispatching for the SNMP
RFC3413 SNMP Applications
RFC3414 User-based Security Model for version 3 of the SNMP (SNMPv3)
RFC3415 View-based Access Control Model for the SNMP
RFC3416 Version 2 of the Protocol Operations for the SNMP
RFC3417 Transport Mappings for the SNMP
RFC3418 MIB for the SNMP
RFC3550 Real-time Transport Protocol (RTP): A Transport Protocol for Real-Time
Applications
RFC3551 RTP Profile for Audio and Video Conferences with Minimal Control
RFC3629 Unicode Transformation Format-8, a transformation format of ISO 10646
RFC3700 Internet Official Protocol Standards
RFC3986 Uniform Resource Identifier: Generic Syntax