Protocols WAN - DSL, SONET, HDLC, DWDM, DLSw +

View

This article describes some of the protocols in the WAN network environments today HDLC implemented business, DSL, SONET, DWDM, and DLSw +

High Level Data Link Control (HDLC)

HDLC is a Cisco proprietary protocol designed for sending data over serial links. It defines a method in which the data link layer encapsulation for data transport on a public or a private network. This protocol is used toTDM leased line circuits. TDM circuits are probably the oldest types of transition from circuit switching technology by the public telephone network, the use of phone is used. The difference is that companies carry data traffic requiring switching speed of 256 Kbps to 45 Mbps is a circuit, the data requires only the beginning and end, what a phone line for conditioning and formatting Data for these speeds.

The TDM network to operateSteps called digital signal zero (DS-0). A DS-0 is a channel of 64 Kbps (56 kbit / s, if in-band signaling is used), which is part of DS-1 field in the standard configuration. A DS-1 defines a standard for the design of transmission over a distance of 1.544 Mbps T1 with 24 channels DS-0. A DS-3 defines a standard for the design of transmission over a distance of 44.736 Mbps T3, DS-1 with 28 channels. Some service providers offer what a fractional T1 (Frac T1). And 'circuit that operates at a lower speedof 1.544 Mbps, as there is a subgroup of the group of 24 channels.

The common fractional T1 speeds 384 Kbps, 6 channels DS-0 is included. Many routers serial interfaces have a function, split-channel or a T1 circuit. This is useful if you do not want to pay for a full T1 circuit. This is done by differentiating each specific channel from full T1 circuit. Europe is called something other standard speed circuit E1and E3. The E1 circuit from 30 DS-0Channels and operates at 2048 Mb / s, while E3 is composed of 20 T1 channels and runs at 34.368 Mbps covers.

Digital Subscriber Line (DSL)

Digital Subscriber Line is a broadband technology, the latest will be used for remote access dial-up access and office. It 'very convenient compared with ISDN and T1circuits, since it is faster and less expensive. The problem with DSL is that you no longer than 18,000 feet must be found by the service station. TheThe demand for Internet access providers high-speed DSL service has installed devices to many key posts. This increases the chances of availability in your neighborhood, if today is not an option. The current specification defines three key technologies, Asymmetric DSL (ADSL), Very High Data Rate DSL (VDSL) and Symmetric DSL (SDSL).

Asymmetric DSL (ADSL), as the name suggests, is the ADSL technology allows fasterspeed downstream service provider to the customer than the upstream speed from client to service providers. The project corresponds to the flow of the Internet and video applications, since they usually have customers send more information to download. Depending on the distance from headquarters to service downstream speed can be faster than 6 Mbit / s upstream speed can be up to 640 kbps. His conservative with bridge taps andlarger wire diameter (gauge) is also the rate of traffic from client to service providers.

The ADSL modem router or client) interface with a standard telephone line pair 2, DSLAM (the termination of the service provider DSL Access Multiplexer at this point. The service cross-connect their DSLAM with a variety of different devices such as T1, T3 , SONET, Frame Relay, ATM or DSL circuits for transmission over the Internet or on adifferent locations. As stated, some customers will use to line sharing ADSL phone and their calls. The DSLAM is split by voice traffic and data traffic to a switch in Class 5, where it is sent over the PSTN using a protocol such as SS7. many business people connect clients opt for a line of further data, the Internet, which increases the cost, however, if the line item is not available, do not concern them.

Very high rate DSL(VDSL) exceeds a specific speed ADSL, telephone lines transmit data at distances between 1,000 meters and 4,500 meters of copper. Distances of about 1000 feet supports speeds of 55 Mbps, while supporting distances of 4500 meters an approximate speed of 12 Mbit / s. There are some technical differences with the line coding, but the modem is the elimination of telephone and ADSL.

Symmetric DSL (SDSL) is something newand as the name suggests, the data transfer in both directions at speeds of T1. The specific distance from headquarters is 21,000 feet, and it should be noted that there is a separate phone line for SDSL will not be severed telephone traffic. This is currently an issue that is addressed, and in this year. SDSL is a service that reduces the always-on connection problems. And the highest rates of upstream traffic to make it more suitable for web-hostinglike downloading files with the downstream traffic is sent with the hand on the upstream traffic. There are huge opportunities for suppliers of marketing services, now have access to affordable Internet access-high speed to many customers in the United States. Telecommuters and business customers to reduce costs at home with a top speed of circuits for transmitting voice and data, use and distribution offices via the Internet.

SONET / SDH

TheSynchronous Optical Network (SONET) specification describes a high-speed fiber service providers of technology to carry voice traffic and data used. A SONET network is constructed with a series of segments, the ring is connected. Each segment is dual SONET rings counter for a diversity link rings should not be available. The standard OC-1 interface is 51.8 Mbps SONET ring network is built with add / drop multiplexers (ADM) that terminate the SONETSignal at various locations national and metropolitan regions. Are time-division multiplexer MUX / DEMUX signals from a SONET OC-12 OC-48 traffic flow. Each ADM has an active and a standby connection to SONET ring. If a power failure is detected with the active compound, the waiting connection is activated immediately. The structure of the SONET frame is 810 bytes, the overhead and payload bytes is included. The overload is the section and line signals includes. The payloadBytes way of signaling and payload are together. Customers like Cisco 7507 that support OC-3 interfaces, ADM with a CAN interface.

Dense Wave Division Multiplexing (DWDM)

Dense Wave Division Multiplexer (DWDM) are used for optical signals at different wavelengths over a single wire multiplex fiber to transport optical network with a speed of 48 to OC-OC-192. Each wavelength can speed up to 10 Gbit / s performance. Recent opticalMultiplex can have up to 100 wavelengths or channels per strand of fiber, nearly a Terabit (1,000 Gbps), the rate of aggregation. Recent efforts on developing multi-terabit traffic on 1 filament fiber concentration. This technology is a sort of demarcation between corporate networks faster and basic long-ISP core networks, which total hundreds of enterprise customers. Enterprise customers can connect with DWDM networks using ATM switches and IP routers with OC-48Interfaces. Public and private network operators SONET rings that connect using devices with interfaces are running at OC-48 speeds as well. The Cisco 12016 Gigabit Switch Router with OC-48 interfaces. Companies today are 400 OC-48 router interfaces to use 12,016 to build a WAN terabit core.

Data Link Switching (DLSw +)

switched data link is a layer 2 protocol used to encapsulate SNA frames over a WAN IP.It is a method, workstations and IP encapsulation SNA Server integrated with the corporate IP network. The encapsulation of SNA is necessary because it does not define a Layer 3 address the protocol stack. Routers using DLSw + is configured to establish peering relationships with local and remote DLSw + routers. Each SNA frame is encapsulated in an IP packet before a WAN router DLSw + peering with cleverly configured. Each end routers local LLC2 Data Link LayerFrames from each local workstation and send confirmations for each local workstation as packets are sent and received. This eliminates the time-out LLC2 problems that can pass between Workstation and Server, if the confirmation should occur during a trip congested WAN circuit.

SNA is a connection and data connection should confirm within a few seconds or the session will timeout. Bridge protocols such as Source-Route Bridging (SRB) limiting the number of bridges and rings, a package SNAmay extend. There is no problem with the number of rings as the DLSw + RIF field is used set to the router. DLSw + integrated many different data-link technologies such as Ethernet, Token Ring, SDLC, and Frame Relay. This is a translation, as well as between different types of frames, such as Ethernet and Token Ring to any router for networking technologies such data. promiscuous mode DLSw + router is configured to allow connections to many remote peer router. An example would be7500 data center routers that peer connections from many sales offices.

Recommend : MP3 Player plantronicsbluetooth hpc4680 hpofficejet6500