#WDM Mux

[katherinewangfs-blog]

Choose the Right SFP+ Transceivers for CWDM Mux Demux

Nowadays, CWDM technology is very popularly used as a easy and economical way to extend the network capacity by carrying several signals with different wavelengths through a signal fiber. If your network capacity is not enough for your daily use, deploying a CWDM system is an ideal choice for you. As the CWDM Mux Demux should be finally linked with the switches in a completed CWDM system, the fiber patch cable and 10G CWDM SFP+ transceiver are required to finish the whole CWDM link. Hence, this paper will mainly introduce the CWDM Mux Demux and choose the right CWDM SFP+ transceivers for the CWDM Mux Demux, which may be helpful for you to fast build a CWDM system.

CWDM Mux Demux–Key Component for CWDM System

CWDM Mux Demux is a key component for CWDM system, which should work in pairs. As an optical module, it can act as a multiplexer or demultiplexer at either end of the fiber cable. This kind of optical Mux Demux is much easier to use than the DWDM Mux Demux, but can not support the network as long as that of the DWDM Mux Demux. In general, it can offers several kinds of wavelengths, usually from 1270nm to 1610nm (20nm spacing), to support the signal transmission at lengths up to 80 km. Meanwhile, the CWDM Mux Demux can be designed with 4 channels, 8 channels, 9 channels, 16 channels and 18 channels for transmitting different amount of signals. To better know how does this kind of WDM Mux work, the following figure offers a reliable 4 channel CWDM Mux Demux duplex transmission design.

From the figure above, we can learn that two CWDM Mux Demux are connected by a length of duplex patch cable, and they are designed with four channels multiplexing the 1470nm, 1490nm, 1510nm and 1530nm over the same fiber. To complete the transmission link, four pairs of CWDM SFP+ transceivers with 1470nm, 1490nm, 1510nm and 1530nm TX and RX should be separately inserted into the ports of these two WDM Mux Demux. When the CWDM system works, the four different signals from the left to the right will be multiplexed in the CWDM Mux, transmitted over the duplex fiber and demultiplexed in the CWDM Demux, and vice versa for the signals from the right to the left.

How to Choose the CWDM SFP+ Transceivers for CWDM Mux Demux?

As mentioned above, the CWDM SFP+ transceivers are required for building a CWDM system which should be correctly inserted into the SFP+ ports of the CWDM Mux Demux. Thereby, here offers three factors that should be taken into consideration when choosing the CWDM SFP+ transceivers for the CWDM Mux Demux.

The first factor is the working wavelengths of the CWDM SFP+ transceivers. In order to ensure the CWDM system performance, the SFP+ transceiver working wavelengths should be the same to the SFP+ ports of the CWDM Mux Demux. Just like the first figure, when the working wavelengths of the first pair of CWDM SFP+ transceivers are 1470 nm, the first ports of the two CWDM Mux Demux should be also 1470 nm, so that the signal with 1470 nm can be successfully transmitted in the CWDM system. As the CWDM working wavelengths are available from 1270 nm to 1610 nm and the channel spacing is 20 nm, there are 18 kinds of working wavelengths for CWDM SFP+ transceivers, as shown in the following figure.

The second factor is the compatibility of the CWDM SFP+ transceivers. As the third party transceivers are more cost effective than the original one, the former kinds are always the choices for most users. However, the users are always unassured about the quality and compatibility of the third party transceivers for their low price. Here FS.COM is recommendable who offers the CWDM SFP+ transceivers fully tested on most famous original brand switches like Cisco, Brocade, Juniper and Arista. FS.COM CWDM SFP+ transceivers are less expensive but can perform as well as the original branded transceivers, without the compatible issue.

The third factor is the transmission distance the CWDM SFP+ transceivers can support. Although the CWDM system can not support the transmission as long as the DWDM one, it still can reach the lengths 80 km. At present, 10G CWDM SFP+ transceiver can be available at lengths of 20km, 40km, 60km, 80km or even longer on the market. Hence, you can also choose the CWDM SFP+ transceivers according to the transmission distance you system needs.

Conclusion

Building a CWDM system for carrying more data signals is a good choice if the existing network has insufficient capacity. To ensure the performance of the whole CWDM link, it is necessasry to choose the right CWDM SFP+ transceivers for the CWDM Mux Demux. From this paper, it can be concluded that there are mainly three factors, the working wavelength, the compatible issue and the transmission distance the CWDM SFP+ supports, should be taken into account when making the decision about which kind of CWDM SFP+ should be selected for the CWDM Mux Demux.

[swiftaugustblog-blog]

DWDM Solutions for Arista 7500E Series Switches

Nowadays, the deployment of DWDM solution has been hotly debated in many enterprise networks, especially in the new Lay2 and Lay3 equipment like Arista 7500E series switches. For many enterprises, DWDM network solutions are undoubtedly the best choices of action, because they can provide a scalable and elastic solution for the enterprise that offered high bandwidth and data separation. This article will demonstrate DWDM solutions to Arista 7500E switches which are the foundation of two-tier open networking solutions for cloud data centers.

Analysis of DWDM System

DWDM (Dense Wavelength Division Multiplexing) is a technology allowing high throughput capacity over longer distances commonly ranging between 44-88 channels and transferring data rates from 100 Mbps up to 100 Gbps per wavelength. For intra-datacenter solutions, an endpoint connection often uses multimode (850 nm) for short ranges and single mode (1310 nm) for longer ranges. The DWDM node converts this local connection to a channelized frequency or wavelength, which is then multiplexed with other wavelength and transmitted over a single fiber connection.

A key advantage of DWDM is that it’s bitrate independent. DWDM-based networks can transmit data in IP, ATM, SONET, SDH and Ethernet. Therefore, DWDM systems can carry different types of traffic at different speeds over an optical channel. Voice transmission, email, video and multimedia data are just some examples of services which can be simultaneously transmitted in DWDM systems.

Arista 7500E 100G DWDM Line Card

With full support for Layer2 and Layer3 protocols, Arista 7500E series switch is the ideal option for the network spine for two tier data centers applications. Arista 7500E especially provides the perfect resolution for high bandwidth Metro and long-haul DCI solutions with the 6-port DWDM line card. It has great advantage to migrate from existing 10G DWDM to 100G coherent line side modules. The 7500E series DWDM line card provides six 100G ports with coherent 100G tunable optics, which enables customers to connect directly into existing WDM MUX module without the need to add transceivers, which can save cost and space to a large extent. The coherent optics use C-band region wavelengths and offer a cost efficient solution for up to 96 channels of 100Gb over a single dark fiber pair.

Use Cases for Arista 7500E DWDM Card

Less Than 80 km Dark Fiber Connection For distance less than 80 km, Arista 7500E switch with DWDM line cards can directly terminate a dark fiber connection with a pair of passive DWDM Mux, thus achieving a point-to-point connection between two locations.

Between 80 km and 150 km Connection For distance greater than 80 km but less than 150 km, losses occurred during the process of transmission should be considered. In order to boost the power level, an EDFA (Erbium Doped Fiber Amplifier) is used to gain flatness, noise level, and output power, which is typically capable of gains of 30 dB or more and output power of +17 dB or more. With the use of EDFA, the signal can be boosted into a certain power level, thus achieving distances of up to 150 km.

Conclusion

The Arista 7500E series DWDM solution offers a cost-effective solution for transporting scalable and massive volumes of traffic, and enhances the 7500E system by providing high performance 100G DWDM port density with the same rich features and dedicated secure encryption in compact and power-efficient systems. Enterprises can easily migrate existing metro and long-haul DWDM networks to add new 100G capacities, thus expanding Layer2 and Layer3 services.

Originally published at http://www.china-cable-suppliers.com/dwdm-solutions-arista-7500e-series-switches.html