September 20, 2002 Week 5: Day 2
Welcome to Lesson 5 - Making Networks Work
Good afternoon!
As promised, you should all have received at least one automated e-mail confirming your quiz grades, and as requested, several of you have contacted us regarding some discrepancies. This automated system is something new we are using in this course, and as with any new technology, there are always a few "bugs" that have to be worked out. Keep letting us know about any issues you have with this or with any part of the course, and we will work diligently to correct them.
This lesson will be rather short, so enjoy, but get prepared for Lesson 6! There's a lot of complicated material you will be covering, so start reading the chapter in the text now!
Lesson 6 should be up on the website on Monday.
Have a good weekend!
Course Notes
IEEE 802 Networking Specifications
The IEEE Project 802 was started to define a set of LAN standards to ensure that network interfaces and cabling from multiple manufacturers would be compatible. (As an interesting side note, 802 stands for February (2), 1980.)
It is also important to note that although the 802 standards predate the OSI
model, they were developed collaboratively and are compatible with each other.
The majority of Project 802’s work was done in the Physical and Data Link layers as evidenced from the following quote from the introduction of RFC948 back in 1985: "The IEEE 802 project has defined a family of standards for Local Area Networks (LANs) that deals with the Physical and Data Link Layers as defined by the ISO Open System Interconnection Reference Model (ISO/OSI). Several Physical Layer standards (802.3, 802.4, and 802.5) [, 3, 4] and one Data Link Layer Standard (802.2) [5] have been defined. The IEEE Physical Layer standards specify the ISO/OSI Physical Layer and the Media Access Control Sublayer of the ISO/OSI Data Link Layer. The 802.2 Data Link Layer standard specifies the Logical Link Control Sublayer of the ISO/OSI Data Link Layer. "
There are currently 12 standards from Project 802 (802.1 through 802.12). The IEEE recognizes that networks are constantly changing and have provided mechanisms for expanding the project as necessary.
A Brief Summary of the Project 802 IEEE Standards - 802.1 - 802.12
| 802.1 - Internetworking | Covers routing, bridging, and internetwork communications |
| 802.2 - Logical Link Control | Relates to error- and flow-control over data frame |
| 802.3 - Ethernet LAN | Covers all forms of Ethernet media and interfaces, from 10Mbps to 1Gbps (Gigabit Ethernet |
| 802.4 - Token Bus LAN | Covers all forms of token bus media and interfaces |
| 802.5 - Token Ring LAN | Covers all forms of token ring media and interfaces |
| 802.6 - Metropolitan Area Network | Covers MAN technologies, addressing, and services |
| 802.7 - Broadband Technical Advisory Group | Covers broadband networking media, interfaces, and other equipment |
| 802.8 - Fiber-optic Technical Advisory Group | Covers use of fiber-optic media and technologies for various networking types |
| 802.9 - Integrated Voice/Data Networks | Covers integration of voice and data traffic over a single network medium |
| 802.10 - Network Security | Covers network access controls, encryption, certification, and other security topics |
| 802.11 - Wireless Networks | Sets standards for wireless networking for many different broadcast frequencies and usage techniques. |
| 802.12 - High-speed Networking | Covers a variety of 100 Mbps-plus technologies including 100VG-AnyLAN |
IEEE Extensions to the OSI Reference Model
It is very important to note that
the IEEE divided the Data Link layer into two sublayers: Logical Link Control
(LLC) and Media Access Control (MAC). See Separation
of Link Layer Functions.
T he MAC sublayer provides shared access for multiple NICs at the Physical layer.
Note, also, that the MAC sublayer is responsible for the physical addressing.
Each network card has a MAC address that identifies it on the network (remember
this from Chapter 4?)
See you next week!
mdm and drw