Structured Cabling

1. What industry standards body and standards series numbers do you need to reference for Ethernet applications and cabling? The IEEE maintains the industry standards for Ethernet Protocols (or applications). This is part of the 802.3 series of standards and includes applications such as 1000Base-T, 1000Base-SX, 10GBase-T, and 10GBase-SR.

2. What are the different types of category 6 cables and what should be recommended this network? Category 6 and category 6A are the types of cables; I would recommend Cat 6A cable over Cat 6 because cat 6A also supports 10Gbps which is for future speed.

3. What cable would you recommend to offer the best shielding performance? You need STP or FIBER OPTIC cable to provide best shielding performance, optic fiber is expensive not easy to terminate ends and has no RFI EMI, whereas shielded twisted pair is easy and cheap.

4. What type of cable would you use for the horizontal spaces and vertical links? Cat6 is the current standard for new installations of Ethernet cable. Depending on the space and certain building codes you need to decide between Plenum (CMP) or Riser (CMR). The difference being Riser cable is more durable, but puts out toxic fumes when caught on fire, so it is not suitable for spaces with open air flow. Dropped ceilings are generally considered Plenum spaces so therefore require plenum cable.

5. What would you look for in trying to find fault if you had the following next and fext problems in 1Gbps links and difficulty meeting 10Gbps performance requirements? When finding fault in NEXT; the crosstalk is usually detected or found at the same end of the cable generating the signal and it is most common between 60 and 90 feet of the transmitter.

In the other hand, when finding faults in FEXT the crosstalk occurs in the other end (opposite) of the cable. the problem is usually too many twists in the cable; Alien Crosstalk (AXT) as the signal rate increase in a cable, this is a major source of interference, and a limiting factor, for running 10GBase-T (10Gbps) over UTP cabling. This kind of crosstalk usually “occurs when the signal being carried in one cable interferes with the signal being carried in “another cables”.

Terms

Osi- (Open Systems Interconnection) this is a standard description or “reference Model” for how messages should be transmitted between any two points in a telecommunication network. Its purpose is to guide product implementers so that their products will consistently work with other products. The reference model defines seven layers of functions that take place at each end of a communication. Although OSI is not always strictly adhered to in terms of keeping related functions together in a well-defined layer, many if not most products involved in telecommunication make an attempt to describe them in relation to the OSI model. It is also valuable as a single reference view of communication that furnishes everyone a common ground for education and discussion.

Developed by representatives of major computer and telecommunication companies beginning in 1983, OSI was originally intended to be a detailed specification of interfaces. Instead, the committee decided to establish a common reference model for which others could develop detailed interfaces that in turn could become standards. OSI was officially adopted as an international standard by the International Organization of Standards (ISO). Currently, it is Recommendation X.200 of the ITU-TS. The main idea in OSI is that the process of communication between two end points in a telecommunication network can be divided into layers, with each layer adding its own set of special, related functions.

Each communicating user or program is at a computer equipped with these seven layers of function. So, in a given message between users, there will be a flow of data through each layer at one end down through the layers in that computer and, at the other end, when the message arrives, another flow of data up through the layers in the receiving computer and ultimately to the end user or program. The actual programming and hardware that furnishes these seven layers of function is usually a combination of the computer operating system, applications (such as your Web browser), TCP/IP or alternative transport and network protocols, and the software and hardware that enable you to put a signal on one of the lines attached to your computer.

The 7 Standard Tcp/IP

Layer 7: The application layer…This is the layer at which communication partners are identified, quality of service is identified, user authentication and privacy are considered, and any constraints on data syntax are identified. (This layer is not the application itself, although some applications may perform application layer functions.) Layer 6: The presentation layer…This is a layer, usually part of an operating system, that converts incoming and outgoing data from one presentation format to another (for example, from a text stream into a popup window with the newly arrived text). Sometimes called the syntax layer.

Layer 5: The session layer…This layer sets up, coordinates, and terminates conversations, exchanges, and dialogs between the applications at each end. It deals with session and connection coordination. Layer 4: The transport layer…This layer manages the end-to-end control (for example, determining whether all packets have arrived) and error-checking. It ensures complete data transfer. Layer 3: The network layer…This layer handles the routing of the data (sending it in the right direction to the right destination on outgoing transmissions and receiving incoming transmissions at the packet level). The network layer does routing and forwarding.

Layer 2: The data-link layer…This layer provides synchronization for the physical level and does bit-stuffing for strings of 1’s in excess of 5. It furnishes transmission protocol knowledge and management. Layer 1: The physical layer…This layer conveys the bit stream through the network at the electrical and mechanical level. It provides the hardware means of sending and receiving data on a carrier.