N10-007 Given a scenario, deploy the appropriate wired connectivity standard

Ethernets

– 10Base2: 10Base2 is defined as part of the IEEE 802.3a standard. The specifications of 10Base2 are:

It is prescribed that of each segment one of the physical end is grounded. The network permits a maximum of five segments out of which only three are allowed to be populated with an upper limit of 30 nodes. It is also required that a distance .5 meters be observed between two nodes

– 10BaseT: This standard specifies an Ethernet network using an unshielded twisted-pair cable. Shielded twisted pair is recommended in cases where interference and attenuation have to be dealt with more proactively. The specifications are:

For extending the length of the segment, repeaters can be used. Using multiple wires that are inside a twisted pair cable, independent transmissions are created for transmitting and receiving data. This allows a full duplex mode to be optionally supported. It can support a large number of computers on its network. The number that can be supported is 1,024. Point-to-Point network design is used. It forms a star topology as one end of the connection is plugged into the card and the other to a hub or a switch.

Fast Ethernet

Gone are the days when even a speed of 10 Mbps was considered fast enough. Businesses demand for more throughput than made available by the above discussed. To meet the needs of speed Fast Ethernet is being preferred as a network design over others. The standards pertaining to Fast Ethernet are specified in the IEEE 802.3u. Discussing these standards in detail:

– 100BaseTX: It is one of the three mentioned under 802.3u standards. The characteristics of this standard are:

It maintains separate paths for transmitting and receiving data and hence supports full duplex operation.

– 100BaseT4: It is the second standard prescribed under this specific category. Its characteristics are:

It uses all the four pairs of wires that are available in the cable. For this reason its transfer is limited to full duplex. The usage of this is not very common.

– 100BaseFX: It is the third of the standards in this category. It is the standard prescribed for running Fast Ethernet over fiber-optic cable. Its characteristics are:

Gigabit Ethernet:

The changing needs of businesses and communication are asking for even faster networks. This has led to a boost to the development of Gigabit Ethernet. It has the potential of 1000Mbps bandwidth and can be used over both fiber as well as copper-based media. The standards include:
– 1000BaseX: It is a collection of the following three standards-

• 000BaseLX: It is a laser standard used over fiber. The LX in the name refers to long wavelength laser. It can be set up over 62.5 micron as well as 50 micron fiber optic cables. It supports the use of single mode fiber. It can achieve greater distances. Its characteristics are:

• Characteristic	Description
  Transfer Rate	1000Mbps
  Distance	Half Duplex 275 meters, Half Duplex 316 meters, Full Duplex 275 meters, Full Duplex 550 meters
  Cable Type	Fiber Optic 5 or higher
  Connector Type	SC, ST
  Transmission Method	Baseband

• 1000BaseSX: It is also a laser standard used over fiber. The SX in the name refers to the short wavelength laser. This can also be set up over 62.5 micron as well as 50 micron fiber optic cables like LX. It is less expensive than LX and its characteristics are:

• Characteristic	Description
  Transfer Rate	1000Mbps
  Distance	Half Duplex 316 meters, Full Duplex 550 meters, Full Duplex 5000 meters
  Cable Type	62.5/125, 50/125 multimode fiber, Two single mode optical fibers.
  Connector Type	Fiber Connectors
  Transmission Method	Baseband

• 1000BaseCX: This standard uses shielded copper wire. The segment lengths are highly restricted and the maximum cable length than can be supported is 25 meters. Its characteristics are:

• Characteristic	Description
  Transfer Rate	1000Mbps
  Distance	25 meters for both full duplex and half duplex
  Cable Type	Shielded copper cable
  Connector Type	9 pin shielded connector
  Transmission Method	Baseband

– 1000BaseT: This is also referred to as 1000BaseTX standard. It is given the designation of IEEE 802.3ab. It permits full duplex transmission that uses the four pairs of the twisted cable. Its characteristics are:

10 Gigabit Ethernet

The hunger for faster data transmission pushes to technology to the next level after every few years. The level of 10 Gigabit Ethernet also known as the 10GbE is the latest in this league and included in the IEEE 802.3ae standard. Data is transmitted at a speed of 10 gigabits per second in these standards. 10 Gigabits=10,000Mbps, which means these standards are 100 times faster. There are numerous versions like 10GBaseSR/SW, 10GBaseLR/LW, and 10GBaseER/EW available in this particular standard.

– 10GBaseSR/SW: 10BaseS is a part the IEEE 802.3ae 10 Gigabit Ethernet specifications. It is used for transmission on multimode fiber. There are two Ethernet standards that fall under the S category. These are 10GBaseSR and 10GBaseSW. Both the standards are for short wavelength multimode fiber. The distance for both the categories is between 2 meters to 300 meters. The SR version is used over dark fiber (unlit fiber) whereas the SW version uses SONET (Synchronous Optical Network) equipment. The SW version is used for longer distance communications.

– 10GBaseLR/LW: These standards cover a greater distance with single mode fiber rather than multi mode fiber. Both the versions are designed for long-wavelength single-mode fiber. As a result, the distance over which it allows transmission varies from 2 meters to 10 kilometers. This range makes the standard suitable for LAN, WAN and MAN setups. The LR standard uses the dark fiber whereas the LW standard connects using SONET equipment.

– 10GBaseER/EW: This standard is used for wide area networks requiring transmissions to be done over greater distances. Both versions are brought into work with extra long wavelength single mode fiber. The distance that this standard allows to be traversed is between 2 meters to 40 kilometers. The ER version is set up with dark fiber and EW with SONET equipment.

The characteristics of the entire group are summarized as:

10GBaseT:

This standard is specified in 802.3an Ethernet standard. It provides 10 Gigabit speed on regular copper cable. It permits a network to upgrade from 1000 gigabit to 10 gigabit network, with the current wiring infrastructure. The characteristics of this particular standard are:

Wiring standards

EIA/TIA has specified a number of categories of twisted-pair cable, some of which are now obsolete. Those still in use today include the following:

• Category 3: Data-grade cable that can transmit data up to 10Mbps with a possible bandwidth of 16MHz. For many years, Category 3 was the cable of choice for twisted-pair networks. As network speeds pushed the 100Mbps speed limit, Category 3 became ineffective.
• Category 4: Data-grade cable that has potential data throughput of 16Mbps. Category 4 cable was often implemented in the IBM Token- Ring Network. Category 4 cable is no longer used.
• Category 5: Data-grade cable that typically was used with Fast Ethernet operating at 100Mbps with a transmission range of 100 meters. Although Category 5 was a popular media type, this cable is an outdated standard. Newer implementations use the 5e standard. Category 5 provides a minimum of 100MHz of bandwidth. Category 5, despite being used primarily for 10/100 Ethernet networking, can go faster. The IEEE 802.11ae standard specifies 1000Mbps over Category 5 cable.
• Category 5e: Data-grade cable used on networks that run at 10/100Mbps and even up to 1000Mbps. Category 5e cabling can be used up to 100 meters, depending on the implementation and standard used. Category 5e cable provides a minimum of 100MHz of bandwidth.
• Category 6: High-performance UTP cable that can transmit data up to 10Gbps. Category 6 has a minimum of 250MHz of bandwidth and specifies cable lengths up to 100 meters with 10/100/1000Mbps transfer, along with 10Gbps over shorter distances. Category 6 cable typically is made up of four twisted pairs of copper wire, but its capabilities far exceed those of other cable types. Category 6 twisted pair uses a longitudinal separator, which separates each of the four pairs of wires from each other. This extra construction significantly reduces the amount of crosstalk in the cable and makes the faster transfer rates possible.
• Category 6a: Also called augmented 6. Offers improvements over Category 6 by offering a minimum of 500MHz of bandwidth. It specifies transmission distances up to 100 meters with 10Gbps networking speeds.

Broadband standards

Now known as CableLabs Certified Cable Modems, DOCSIS (Data Over Cable Service Interface Specifications) is a standard interface for cable modems, the devices that handle incoming and outgoing data signals between a cable TV operator and a personal or business computer or television set. DOCSIS 1.0 was ratified by the International Telecommunication Union (ITU-TS) in March of 1998. Although “DOCSIS” continues to be used, the newer name emphasizes that the standard is now being used to certify the products of cable modem makers. Cable modems conforming to DOCSIS are now being marketed.

Cable operators whose existing customers have non-standard cable modems can handle them by adding backwards-compatible support to the DOCSIS card at the cable operator’s end. As DOCSIS continues to evolve to new versions, existing modems can be upgraded to the newer versions by changing the programming in the cable modem’s EEPROM memory. DOCSIS-compliant cable modems are being integrated into set-top boxes for use with television sets. DOCSIS must also support or converge with the high definition television (HDTV) standard. The set-top box itself follows a standard known as OpenCable.

DOCSIS specifies modulation schemes and the protocol for exchanging bidirectional signals over cable. It supports downstream-to-the-user data rates up to 27 Mbps (megabits per second). Since this data rate is shared by a number of users and because many cable operators will be limited by a T1 connection to the Internet, the actual downstream data rate to an individual business or home will be more like 1.5 to 3 Mbps. Since the upstream data flow has to support much smaller amounts of data from the user, it’s designed for an aggregate data rate of 10 Mbps with individual data rates between 500 Kbps and 2.5 Mbps.

Cisco and Microsoft have endorsed DOCSIS. They are collaborating on a DOCSIS-compliant cable hybrid fiber-coax (HFC) system, called the Multimedia Cable Network System (MCNS) that will deliver services to residential, commercial, and educational customers.