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Ason Technology And Network Evolution

Abstract ASON technology is the development of optical transport network a major breakthrough, the paper discusses the advantages of ASON networks as well as the relationship between SDH and OTN, ASON is discussed in detail the transmission plane, control plane, and network management features and progress of the plane, and finally for the optical transport network evolution strategy to the ASON may be analyzed.

  Keywords automatic switched optical network user network interface synchronous digital sequence quality of service

2000 years later, the optical transport network technologies there are new developments, mainly automatic switched optical network (AutomaticallySwitched OpticalNetwork, ASON) the emergence of its most prominent feature is the introduction of an independent transmission network intelligence control plane, control plane to complete the routing using automatic discovery, call connection management, protection and restoration, so as to implement the dynamic call connection to the network management.

ASON draws heavily on the exchange and data technology, to exchange, transfer and data in three areas has added a new intersection. Various manufacturers and operators of the technology have been given due attention. This will be the key technology and its progress ASON discussed in detail and based on current national transmission network operators, the characteristics of the technical evolution of the program may be discussed.

1 ASON technical characteristics 1.1 ASON advantages ASON is a service request initiated by the users, automatic routing, signaling control achieved by the connection establishment / removal, financial exchange and transfer as one of the next-generation optical network.

Combined with the domestic transmission network operator status, ASON technology can solve the transmission network into three major technical challenges faced:

(1) the issue quickly to provide circuit

ASON most important feature is to quickly provide the circuit, using a distributed control can provide orders of magnitude in the second end of the circuit, the rate for 155Mbit / s, 2.5Gbit / s and so on. Businesses reduce the time help operators gain more customers and profit.

(2) transmission circuit QoS issues Transmission circuit current level of basic services can not be developed in accordance with the appropriate tariff policy, resulting in waste of resources, and ASON on the circuit can easily divide the priority to provide a service level agreement (SLA) of transmission circuits.

(3) can provide fast protection and restoration

Mostly rely on existing transmission network SDH rings to be protected, but the circuit efficiency is low, only 50%, while on the cross-ring circuit can not be effectively protected. The ASON can effectively solve the circuit protection and restoration can be completed in the second magnitude, and the cost of spare circuit less resources, general resources for the work of the circuit for 30% to 60%, well below the SDH ring network.

1.2 ASON and SDH, OTN relationship

Automatically switched optical network is divided into transmission plane, control plane and management plane in three parts. Transmission plane including the exchange of entities from the transmission network composed of network elements, is the realization of the connection establishment / removal, exchange and transfer of the physical plane. The introduction of ASON control plane is different from the traditional transport network is a fundamental point, which includes a series of real-time signaling and protocol system to realize the connection establishment, release control and monitoring, maintenance and other functions, the signaling control plane network support. Management plane is the control plane and transmission of the management plane.

ASON control plane is suited to the OTN (optical transport network), also applies to SDH, the transmission network as a unified control plane. SDH, OTN and ASON in the relationship can be expressed in Figure 1.

Can be seen from Figure 1, a separate SDH / OTN and does not constitute ASON, to constitute the ASON must SDH / OTN + plane + next-generation network management control plane (management and control can also plane and the transmission plane), three are indispensable. SDH, OTN transmission plane only ASON technology, ASON and SDH, OTN and does not contain relations.

2 ASON Technical Development 2.1 Technology transfer plane As the current line rate

reached 1.6Tbit / s, line capacity issue has been resolved. Transmission plane sent the most prominent problem is the node that the transmission network in the optical / electrical cross-machine, optical / electrical cross-machine is the core of transmission plane, the size of its processing capacity related to the ASON throughput and processing power, particle size .

Wavelength cross-current to achieve high capacity in three ways: The first is the all-optical switching, the second is the use of O / E / O (optical / electrical / optical) processing to achieve, the third is the photoelectric hybrid method. All-optical methods due to its stability and fault detection and location problems, is still in the experimental stage, commercialization will take some time. The opto-electronic hybrid approach the challenges facing the same way with all-optical. Now it seems the use of optical / electrical / optical approach is the mainstream product, especially in SDH-based optical / electrical / optical cross-machine (can be cross-VC-4 level). With the advent of large-capacity cross-chip (currently single cross-chip can reach 160Gbit / s and above), the core cross-cutting capacity of Tbit / s is not very difficult. To the market has been commercial-oriented 1.28Tbit / s products as an example, assume that input and output ports of the processing rate of 10Gbit / s, the cross-matrix of size 128 × 128 should be more than the capacity of its external service access 1.28Tbit / s. This rate of capacity is appropriate for the current network, although route on the backbone WDM System is 32 × 10Gbit / s, but the actual with the wavelength is usually 4 to 8, assuming that each line has eight wavelengths need to be processed, the matrix can be cross-direction of the end of the 16 WDM line. Even for such a core transmission node Beijing, currently meet the requirements. Using optical / electrical / optical mode is a characteristic of other low-level VC can cross to achieve a low rate of integration and aggregation, network more easily.

Optical / electrical / optical methods can support high-capacity cross-Machine VC-4 and VC-4-Xc level crossing. In the external interface is generally 2.5 Gbit / s, 10Gbit / s, can be G.707 SDH interface or G.709 OTN interfaces. SDH interface supports 2 fiber, 4 fiber MS-Spring multiplex section protection ring. As the connection status monitoring by the sending side must initiate the connection point and end point detection signal quality; for SDH, OTN, you can use SDH, OTN overhead for performance monitoring and fault management, such as SDH monitoring bytes B1, J0 , control surfaces need

Network Interface Cards (NIC)

A NIC (network interface card) is designed to speak over a computer network. It allows users to attach to every different either by using cables or wirelessly if the NIC could be a wireless NIC (WiFi/WNIC). Each entity on a network, a PC, printer, router, etc., that desires to communicate with other devices should have a NIC if it is to speak over the network. On older computers, the NIC is most likely an growth card, typically PCI or PCI express. High performance cards will value less that . NIC functionality is now usually integrated into the motherboard chipset or implemented with an infatuated Ethernet chip on the motherboard.

An analogous scenario is true for laptop computers. At just the once, a PCMCIA network card would be employed in a laptop pc for the NIC just because the PCI card was utilized in desktop pc, however currently, NIC functionality is usually integrated with the motherboard.

Ethernet is that the dominant normal for cable connections for wired computer networks.

An Ethernet connector looks almost like a telephone connector, solely larger. This connector is termed “RJ45″. Ethernet cables are either a shielded or unshielded cable of four twisted pairs of twenty four AWG connectors, specified at a hundred ohm impedance. Maximum cable length for CATX cables is a hundred meters.

Early versions of Ethernet cables were CAT3 or CAT4 (CAT being short for category). These versions weren’t long lived. CAT5 and CAT5e are currently the most commonly used cables (bandwidth of a hundred MHz, a hundred Mbps), with CAT6 (bandwidth of 250 MHz, 1 Gbps) out there and the configuration of the near-future. A CAT7 cable (bandwidth of 600 MHz) specification is in development, and ought to be obtainable in an exceedingly few years.

Every Ethernet NIC has a distinctive serial range called a “media access code” (MAC address) that’s used to spot the NIC and associated laptop on the network. No two NIC will have the same address, as a result of the NIC makers should purchase blocks of addresses from the Institute of Electrical and Electronics Engineers (IEEE).

NIC cards are capable of various speeds. Speeds of up to one gigabit per second (Gbps) are now available. 2 NIC will communicate if they differ in speed ratings, but they can communicate at the rate of the slower NIC.

On a very simple network, NIC will be used to link personal computers (PC). If the computers are connected directly to at least one another, the network is a “peer-to-peer” (P2P, additionally referred to as an “circumstantial”) network. If computers are connected directly to 1 another, a “cross-over” Ethernet cable is required (additionally referred to as a “Null-Modem cable”). This cable is not “straight-through” like customary Ethernet, however crosses the send and receive connectors, so that send line from pc A connects to the receive line of laptop B.

For networks of a few computers, a “hub” will be used, with all of the computers connected to the hub. Any message sent from any PC will be seen by all of the computers, however solely the computer with the correct MAC address will receive the message. P2P networks are helpful for many purposes. File and printer sharing are the foremost common applications.

Networks with more than four active computers at a time can benefit from employing a “network switch” rather than a hub. A network switch can direct the message to the acceptable destination, instead of each message packet being broadcast across the network. Laptop A will send a message to pc B, whereas simultaneously, pc C sends a message to pc D. This increases the efficiency of the network. This is a easy kind of a server network. An example of a client-server style is a computer server where the purchasers initiate a download or upload of files and therefore the server reacts. The server would also typically be accountable for interacting with printers and different servers on different networks, including satellite networks (SATCOM) or the Internet.

“Latency” is that the delay caused by a network to communicate data. Latency causes not solely slow service, however will result in information loss as well. Latency is typically tested by sending a message packet that is immediately returned to the sending computer. The round-trip time is defined as the latency.

Networking performance will be optimized for either latency or throughput. Networks will use a way known as “interrupt moderation” to increase throughput and lower CPU utilization by queuing message packets and issuing fewer interrupts to the CPU. A network optimized this method would favor large transfers, reducing transfer overhead. CPU and network throughput benefit, however network latency would increase. The alternative is to fragment every message and pipeline the fragments through the network. Multiple methods from supply to destination will permit overlapping. Latency will also be addressed with techniques like prefetching (anticipating the requirement for knowledge requests) and/or using multiple execution threads (multithreading).

There are two indicator LEDs on a typical NIC. One lit inexperienced LED indicates the pc is connected to the network. This can be called the “link” light. The second LED is amber in color. A flashing amber LED indicates message packet collisions are occurring. Occasional collisions are traditional on a busy network, but a frequently lit amber LED is a sign of problems. A quickly flashing link LED (green) could be a network activity indicator, that means that communication is occurring. If the inexperienced link lightweight is off, and also the amber LED is blinking, then the NIC is in “power save” mode.

A wireless network interface controller (WNIC) could be a NIC for connecting to a wireless network (WiFi). The quality for WiFi is IEEE 802.11. A WNIC uses an antenna to speak with an Rf signal, most typically at 2.4 GHz. Wireless connectivity development in recent years has closely paralleled wired connectivity. Like its wired cousin, a wireless card was once integrated with a PCI or PCMCIA add-on card. Now, integrated WNIC’s are changing into common, especially for laptop computers.