Classification of Dynamic Routing Protocols

Routing protocols can be classified into different groups according to their characteristics. The most commonly used routing protocols are: RIP, IGRP, OSPF, IS-IS, EIGRP, BGP

• RIP - A distance vector interior routing protocol
• IGRP - The distance vector interior routing developed by Cisco (deprecated from 12.2 IOS and later)
• OSPF - A link-state interior routing protocol
• IS-IS - A link-state interior routing protocol
• EIGRP - The advanced distance vector interior routing protocol developed by Cisco
• BGP - A path vector exterior routing protocol

Physically Connecting a WAN Interface

The WAN Physical layer describes the interface between the data terminal equipment (DTE) and the data circuit-terminating equipment (DCE). Generally, the DCE is the service provider and the DTE is the attached device. In this model, the services offered to the DTE are made available either through a modem or a CSU/DSU.

Typically, the router is the DTE device and is connected to a CSU/DSU, which is the DCE device. The CSU/DSU (DCE device) is used to convert the data from the router (DTE device) into a form acceptable to the WAN service provider. The CSU/DSU (DCE device) is also responsible for converting the data from the WAN service provider into a form acceptable by the router (DTE device). The router is usually connected to the CSU/DSU using a serial DTE cable, as shown.

Serial interfaces require a clock signal to control the timing of the communications. In most environments, the service provider (a DCE device such as a CSU/DSU) will provide the clock. By default, Cisco routers are DTE devices. However, in a lab environment, we are not using any CSU/DSUs and, of course, we do not have a WAN service provider.(more information)

Ethernet Connector

A different connector is used in an Ethernet-based LAN environment. An RJ-45 connector for the unshielded twisted-pair (UTP) cable is the most common connector used to connect LAN interfaces. At each end of an RJ-45 cable, you should be able to see eight colored strips, or pins. An Ethernet cable uses pins 1, 2, 3, and 6 for transmitting and receiving data.

Two types of cables ..

can be used with Ethernet LAN interfaces:

• A straight-through, or patch cable, with the order of the colored pins the same on each end of the cable
• A crossover cable, with pin 1 connected to pin 3, and pin 2 connected to pin 6

Straight-through cables are used for:

• Switch-to-router
• Switch-to-PC
• Hub-to-PC
• Hub-to-server

Crossover cables are used for:

• Switch-to-switch
• PC-to-PC
• Switch-to-hub
• Hub-to-hub
• Router-to-router
• Router-to-server

Connection for WAN

For WAN connections, Cisco routers support the EIA/TIA-232, EIA/TIA-449, V.35, X.21, and EIA/TIA-530 standards for serial connections, as shown. Memorizing these connection types is not important. Just know that a router has a DB-60 port that can support five different cabling standards. Because five different cable types are supported with

this port, the port is sometimes called a five-in-one serial port. The other end of the serial cable is fitted with a connector that is appropriate to one of the five possible standards.(more information)

IBM helps companies in cutting emissions and costs

International Business Machines Corp. (IBM) consulting tool on Thursday that allows both companies to reduce costs and carbon dioxide emissions in the supply chain mereka.hal aim to reduce the bad impact of the environment.

Built with brand-IBM software, Supply Chain Network Optimization Workbench (Snow) to help the client to check the number of distribution centers and they must decide whether to conduct its own production or through third parties.

In tests, the Chinese logistics company and shipper COSCO Ltd system that is used to reduce the number of distribution centers use up to 40 from 100, lowering the cost by 23 percent and cut carbon dioxide emissions by 15 percent, IBM said.

"When you increase the efficiency of the system you can almost automatically reduce costs, waste, and environmental impact," Eric Riddleberger, head of IBM's business strategy consulting practice, said in a statement.

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