Category Archives: Network Solutions

Cat6 Cables for Data Center Applications

The trend in network has always been leaning towards the higher bandwidth. Upgrading to a Cat6 cables (including Cat6a) system can ensure transmission speed and sustained performance for processing needs. Especially for data centers, investing into a higher-grade system will increase the network’s capacity and performance.

Cat6 Cables Overview

Conformed with EIA/TIA/IEEE standards, Cat6 cabling system includes patch cables, pre-terminated trunk cables, and bulk cables. For most first-class suppliers, their Cat6 Ethernet cables, involving Cat6a ethernet cables have 100% passed the Fluke Test, and deliver a specified testing report. Generally, Cat6 network cables adopt oxygen-free copper conductor with high electrical conductivity and low signal transmission attenuation. Being backward compatible with all the previous categories, cable UTP Cat6 and cable SFTP Cat6 both can be used to support up to 10 Gigabit Ethernet speed, and operate at up to 250MHz (Cat6a at 500MHz).

Cat6 Patch Cables

 

Cat6 Ethernet patch cables consist of Cat6, Cat6a, and slim Cat6 patch cables. According to length like 100ft Cat6 Ethernet cable, color, cable jacket, and shielding type, different Cat6 can be found in the market. Usually, the conductor of Cat6a and Cat6 shielded cable is 26AWG. The Cat6 unshielded cable is 24AWG, and the slim Cat6 is 28AWG. With a transmission distance up to 100m, Cat6 patch cables are widely used in data centers, network cabinets, offices to connect any data transmission equipment, such as PoE switches.

Cat6 Patch Cables

Figure 1: Cat6 Patch Cables

Cat6 Pre-terminated Trunk Cables

 

For Pre-terminated trunk cable, UTP Cat6 and SFTP Cat6a are available. Altogether, there are plug to plug type and jack to jack type can be found in the market. Generally, the conductor of jack to jack type is 23 AWG, while the plug to plug type is 26AWG. When it comes to the Cat6 cable price per meter, the plug to plug Cat6 cable price and Cat6a cable price are much higher than jack to jack types like jack to jack Cat6 UTP price. As for applications, Cat6 pre-terminated trunk cable assemblies are used to improve efficiency and reduce labor cost and waste in large infrastructures with high-density cross-connection and patching systems.

Cat6 Pre-terminated Trunk Cables

Figure 2: Cat6 Pre-terminated Trunk Cables

Cat6 Bulk Cables

 

Complied with IEEE 802.3af and IEEE 802.3at for PoE applications, most Cat6 bulk cables (including Cat6a) are about 1000ft (305m) lengths with spools. Their conductors are about 23 AWG. This Cat6 cable type is premium cabling designed for Cat6 or Cat6a applications, such as connecting an Ethernet wall jack to a router, patch panel or switch. With fast transmission and excellent signal quality, it ensures peak performance through your LAN.

Cat6 Bulk Cable

Figure 3: Cat6 Bulk Cable

Cat6 Cabling Application in Data Center

As we mentioned in the previous part, Cat6 cables consist of patch cables, pre-terminated trunk cables, and bulk cables. Each Cat6 cable type has its own features, which can be deployed into different scenarios. Here, we will take the integrated cabling of Cat6 pre-terminated trunk cable and Cat6 Ethernet patch cable types as a case to demonstrate its application in data center.

Cat6 Cabling Solution Case:

 

Cat6 Cables Data Center Application

Figure 4: Cat6 Cables Data Center Application

As the Cat6 wiring diagram shown above, we can find in this scenario, there are two racks in this data center needed to do cabling. And in each side, there is one FS S3900-24T4S switch. In that case, the first thing you need to do is to consider how to do Cat6 wiring and what’s the Cat6 wire order. Firstly, for the switch connection, the regular Cat6 patch cables will be used undoubtedly. As for connecting the two racks, the jack to jack trunk cable is suggested to use to do cross-connection. After that, cable managers and cable ties are recommended to deploy to keep the cables organized effectively. For suggested products list, you can refer to the following chart.

Suggested Products:

 

 Products List

Figure 5: Products List

Conclusion

As a cost-effective solution, Cat6 cables have been widely applied in all kinds of 1G/10G networks, especially in data centers. How to have a flexible and economically cabling system matters a lot to data center users. Hope this article can give you some inspirations.

DWDM Network over Long Distance Transmission

With the ever-increasing need for higher bandwidth, DWDM technology has been one of the most favorable optical transport network (OTN) applications. In this post, we will reveal FS.COM DWDM-based network solutions over various transmitting distances as well as some suggestions for the DWDM networks deployment.

DWDM Networks Basics

As usual, let’s review some basics of DWDM networks. In this part, we will figure out two questions: What is DWDM? What are the components of DWDM networks?

DWDM Technology
DWDM Networks

Figure 1: DWDM Networks

DWDM (Dense Wavelength Division Multiplexing) is an associate extension of optical networking. It can put data signals from different sources together on a single optical fiber pair, with each signal simultaneously carried on its own separate light wavelength. With DWDM, up to 160 wavelengths with a spacing of 0.8/0.4 nm (100 GHz/50 GHz grid) separate wavelengths or channels of data can be transmitted over a single optical fiber.

DWDM Networks Components

Conventionally, for DWDM networks, there are four devices showed as below that are commonly used by IT workers:

  • Optical transmitters/receivers
  • DWDM mux/demux filters
  • Optical add/drop multiplexers (OADMs)
  • Optical amplifiers transponders (wavelength converters)

DWDM Networks Over Long Distance Transmission Solutions

Scenario 1: 40 km Transmission
40km DWDM Network

Figure 2: 40km DWDM Network

For this case, the 80km DWDM SFP+ modules and 40ch DWDM Mux/Demuxs are recommended to use. Since the 80km DWDM SFP+ modules are able to support 10G transmission over 40 km, no additional device is needed under this scenario.

Scenario 2: 80 km Transmission
80km DWDM Network

Figure 3: 80km DWDM Network

Deploying this 80 km DWDM network, we will still use 80km DWDM SFP+ modules and 40ch DWDM Mux/Demuxs. The light source of 80km DWDM SFP+ modules might not be able to support such long transmission distance, as there might be a light loss during transmission. In this case, pre-amplifier (PA) is usually deployed before the location A and location B to improve the receiver sensitivity and extend signal transmission DWDM distance. Meanwhile, the dispersion compensation module (DCM) can be added to this link to handle the accumulated chromatic dispersion without dropping and regenerating the wavelengths on the link. The above diagram shows the deploying method of this 80km DWDM network.

Scenario 3: 100 km Transmission
100km DWDM Network

Figure 4: 100km DWDM Network

Under this scenario, the devices used in scenario 2 still need to remain. Since the transmission distance has been increased, the light power will be decreased accordingly. Besides that, you will also need to use booster EDFA (BA) to amplify the optical signal transmission of the 80km DWDM SFP+ modules.

By the way, if you want to extend DWDM transmission distance, you can read this post for solutions: Extend DWDM Network Transmission Distance With Multi-Service Transport Platform.

Factors to Consider in Deploying DWDM Networks

1. Being compatible with existing fiber plant. Some types of older fiber are not suitable for DWDM use. Currently, standard singlemode fiber (G. 652) accounts for the majority of installed fiber, supporting DWDM in the metropolitan area.

2. Having an overall migration and provisioning strategy. Because DWDM is capable of supporting massive growth in bandwidth demands over time without forklift upgrades, it represents a long-term investment. Your deployment should allow for flexible additions of nodes, such as OADMs, to meet the changing demands of customers and usages.

3. Network management tools. A comprehensive network management tool will be needed for provisioning, performance, monitoring, fault identification and isolation, and remedial action. Such a tool should be standards-based (SNMP, for example) and be able to interoperate with the existing operating system. For example, the FMT DWDM solutions from FS.COM are able to support kinds of network management, including NMU line-card, monitor online, simple management tool, and SNMP.

4. Interoperability issues. Because DWDM uses specific wavelengths for transmission, the DWDM wavelengths used must be the same on either end of any given connection. Moreover, other interoperability issues also need to be considered, including power levels, inter- and intra-channel isolation, PMD (polarization mode dispersion) tolerances, and fiber types. All these contribute to the challenges of transmission between different systems at Layer 1.

5. Strategy for protection and restoration. There might have hard failures (equipment failures, such as laser or photodetector, and fiber breaks) and soft failures such as signal degradation (for example, unacceptable BER). Therefore, you need to have a protection strategy while deploying a DWDM network.

6. Optical power budget or link loss budget. Since there might be an optical signal loss over the long distance transmission, it’s critical to have a link loss budget in advance.

Summary

Bringing great scalability and flexibility to fiber networks, the DWDM networks solutions obviously enjoys plenty of strengths, which is also proved to be future-proof. In this post, we make a revelation of the DWDM-based network over long distance transmission. Also, some tips for deploying a DWDM network has also been shared for your reference.

An Overview on EVPN and LNV

Bombarded with assorted network applications and protocols, the technologies and solutions for network virtualization delivery have been enriched greatly over past years. Among those technologies, VXLAN, also called virtual extensible local area network, is the key network virtualization. It enables layer 2 segments to be extended over an IP core (the underlay). The initial definition of VXLAN (RFC 7348) only relied on a flood-and-learn approach for MAC address learning. Now, a controller or a technology such as EVPN and LNV in Cumulus Linux can be realized. In this post, we are going to make an exploration on those two techniques: LNV and EVPN.

VXLAN

Figure 1: VXLAN

What Is EVPN

EVPN is also named as Ethernet VPN. It is largely considered as a unified control plane solution for the controller-less VXLAN, allowing for building and deploying VXLANs at scale. The EVPN relies on multi-protocol BGP (MP-BGP) to transport both layer 2 MAC and layer 3 IP information at the same time. It enables a separation between the data layer and control plane layer. By having the combined set of MAC and IP information available for forwarding decisions, optimized routing and switching within a network becomes feasible and the need for flooding to do learning gets minimized or even eliminated.

What Is LNV

LNV is the short of lightweight network virtualization. It is a technique for deploying VXLANs without a central controller on bare metal switches. Typically, it’s able to run the VXLAN service and registration daemons on Cumulus Linux itself. The data path between bridge entities is established on the top of a layer 3 fabric by means of a simple service node coupled with traditional MAC address learning.

The Relationship Between EVPN and LNV

From the above wiki of the EVPN and LNV, it’s easy for us to notice these two technologies are both the applications of VXLAN. For LNV, it can be used to deploy VXLAN without an external controller or software suite on the bare-metal layer 2/3 switches running Cumulus Linux network operating system (NOS). As for EVPN, it is a standards-based control plane for VXLAN, which can be used in any usual bare-metal devices, such as network switch and router. Typically, you cannot apply LNV and EVPN at the same time.

Apart from that, the deployments for EVPN and LNV are also different. Here, we make a configuring model for each of them for your better visualization.

EVPN Configuration Case

 

EVPN

Figure 2: EVPN

In the EVPN-VXLAN network segments shown in Figure 2 (Before), hosts A and B need to exchange traffic. When host A sends a packet to host B or vice versa, the packet must traverse the switch A, a VXLAN tunnel, and the switch B. By default, routing traffic between a VXLAN and a Layer 3 logical interface is disabled. If the functionality is disabled, the pure Layer 3 logical interface on the switch A drops Layer 3 traffic from host A and VXLAN-encapsulated traffic from the switch B. To prevent the pure Layer 3 logical interface on the switch A from dropping this traffic, you can reconfigure the pure Layer 3 logical interface as a Layer 2 logical interface, like Figure 2 (After). After that, you need to associate this interface with a dummy VLAN and a dummy VXLAN network identifier (VNI). Then, an Integrated routing and bridging (IRB) interface need to be created, which provides Layer 3 functionality within the dummy VLAN.

LNV Configuration Case

 

LNV

Figure 3: LNV

The two layer 3 switches are regarded as leaf 1 and leaf 2 in the above figure. They are running with Cumulus Linux and have been configured as bridges. Containing physical switch port interfaces, the two bridges connect to the servers as well as the logical VXLAN interface associated with the bridge. After creating a logical VXLAN interface on both leaf switches, the switches become VTEPs (virtual tunnel end points). The IP address associated with this VTEP is most commonly configured as its loopback address. In the image above, the loopback address is 10.2.1.1 for leaf 1 and 10.2.1.2 for leaf 2.

Summary

In this post, we have introduced the two techniques of network virtualization: EVPN and LNV. These two applications of network virtualization delivery share some similarities, but also quite a lot of differences. Being satisfied with the simplicity, agility, and scalability over the network, the EVPN has been a popular choice in the market.

What Cable Should I Use for 10G Transceiver Module?

To deploy the optical network, the transceiver module and patch cable are the two basic components. According to the feedbacks of customers from FS.COM, one of the common problems faced by them is what cables they should use for their transceiver modules. To solve this problem, we make this post of patch cable selection guidance. Since the order for 10G transceivers ranks top, we are going to take 10G modules as a reference.

An Overview of 10G Transceiver Module

Transceiver module, also called fiber optic transceiver, is a hot-pluggable device that can both transmit and receive data. By combining a transmitter and receiver into a single module, the device converts electrical signals into optical signals to allow these signals to be efficiently transferred on fiber optic cables. As for the 10G transceiver, it refers to the optical modules with 10G data rate. In FS.COM, there are mainly four types of 10G transceivers: XENPAK, X2, XFP, and SFP+. Even though these optical transceivers are all accessible to the 10G networks, they have different matching patch cables and applications.

10G Transceiver Module

Figure 1: 10G Transceiver Modules

Patch Cable Basics

Apart from optical module, the patch cable is the other vital role in networking. Patch cable, also called patch cord, refers to the copper or optical cable. It’s designed to connect one electronic or optical device to another for signal routing. Conventionally, the patch cable will be terminated with connectors at both ends. For example, the LC fiber cable refers to the optical cable fixed with LC connector. Typically, there are LC, SC, ST, FC and MTP/MPO fiber patch cables. According to different features, we can get various classifications of patch cables, such as fiber types, polishing types, etc.

Patch Cables

Figure 2: Patch Cables

Factors to Consider When Choosing Patch Cable for 10G Transceiver Module

Recently, most of the 10G transceiver modules are compatible with different brands and support higher data rates. It will be much easier to choose optical modules for your networking than selecting mating patch cables. Based on most applications, there are three major factors that can be taken into consideration: transmission media, transmission distance, and transceiver module interface.

Transmission Media

Classified by transmission media, two types of patch cables can be found in the market: optic fiber cable and copper cable. Correspondingly, there are two kinds of optical transceivers available: copper-based transceivers and fiber optic based transceivers. Copper transceiver modules like 10GBASE-T SFP+, they have an RJ45 interface, connecting with copper cables. Typically, Ethernet cables that support 10G copper-based transceivers are Cat7 and Cat6a cables.

As for the 10G optical modules, they can support higher data rates over optic fiber cables. It will be more complicated to choose fiber cables. Generally, there are multimode fibers and single mode fibers. Based on the specified needs for transmission distance, the answer will be varied.

Transmission Distance

To select cables, the transmission distance is also an important factor that you need to take care. In the following table, we list the basic information of common 10G transceivers, including their supporting fiber cable types and transmitting distance.

Transceiver Type
Wavelength
Cable Type
Transmission Distance
SR
850 nm
MMF
300 m
LR
1310 nm
SMF
10 km
ER
1550 nm
SMF
40 km
ZR
1550 nm
SMF
80 km

As for fiber cables, single mode fiber is used for long-distance transmission and multimode fiber is for short distance. In a 10G network, the transmission distance of single mode fiber (OS2) can reach from 2 km to 100 km. When it comes to multimode fibers, the transmission distances for OM1, OM2, OM3 are 36 m, 86 m and 300 m. OM4 and OM5 can reach up to 550 m.

Transceiver Module Interface

Another factor you need to consider is the transceiver interface. Usually, transceivers use one port for transmitting and the other port for receiving. They tend to employ duplex SC or LC interface. However, for 10G BiDi transceivers, it only has one port for both transmitting and receiving. Simplex patch cord is applied to connect the 10G BiDi transceiver.

Summary

For your 10G network cabling, transceiver module and patch cable are necessary components. With a wide range of patch cables, selecting the right patch cables will be more complex than 10G transceivers. Generally, three major factors can be considered: transmission media, transmission distance, and transceiver module interface. To apply what you have learned in this post in cabling, you can visit FS.COM for all the transceivers and patch cables at one shop.

How to Troubleshoot Transceiver and Switch Port Through Loopback Test?

Loopback

Loopback is a commonly used term in telecommunications. It refers to the process of transmitting electronic signals or digital data streams and returning to their sending point without any intentional processing or modification. Therefore, by comparing transmitting signals with the receiving signals, the loopback test is used to debug physical connection problems. But what a loopback test means for fiber optic network and how to make use of it will be the issues that we will explore in this post.

Why Need Fiber Loopback Test?

To conduct a fiber loopback test, the communication devices will be involved, like the transceivers and the switch. As you know, the transceiver is the basic component of fiber optic communication network equipment. We can take the transceiver as a case. Conventionally, a transceiver has a transmitting port and a receiving port, in that way, the loopback test can be applied to test the ports to diagnose whether the transceiver is working well and the configuration of the switch is right. For its unique working mode, the test is a convenient way to maintain transceivers. In the next part, we will deliver how to do the fiber loopback test on the transceiver.

How to Conduct Loopback Test?

In this part, we will introduce two types of tests to troubleshoot transceiver and switch port: single-port test and dual-port test.

Tools You Need to Prepare

To perform tests, things you need to prepare are listed below:

  • Transceivers (2pcs), such as 10G SFP+ SR transceiver.
  • Simplex fiber cable (1 pc).
  • Switch (1 pc), like Cisco switch.
  • Duplex fiber cable (1 pc).
  • Two loopback cables (optional), like LC or SC loopback cable. To know more about loopback cable, you can move to the article: What Is Loopback Cable And How to Use It?
Loopback Cable

Figure 1: Loopback Cable

Loopback Test Steps
Single-port Loopback Test
Single-port Loopback Test

Figure 2: Single-port Loopback Test

1. Connect your transceiver with one simplex fiber cable or loopback cable, such as LC fiber cable or LC loopback cable. At this step, you can examine whether the port and transceiver parameters are normal.

2. Check the software version of the switch.

3. Review the interfaces status to confirm the working status of all ports on the switch.

Display the Working Status of All Ports

Figure 3: Display the Working Status of All Ports

4. Check the working status of the port you are connecting, such as the port 50 in the following figure.

Working Status of Interface 50

Figure 4: Working Status of Interface 50

5. Go over the DDM information to review whether the transceiver works in normal status.

DDM Information of Port 50

Figure 5: DDM Information of Port 50

Dual-port Loopback Test
Dual-port Loopback Test

Figure 6: Dual-port Loopback Test

1. Connect two transceivers with one duplex fiber cable or two loopback cables. At this step, you can examine whether the port and transceiver data rate are matching as well as the link is normal or not.

2. Check the interfaces status to confirm the working status of all ports on the switch.

Ports Working Status Display

Figure 7: Ports Working Status Display

3. Check the working status of the two ports you are connecting, such as the ports 50 and 52 in the following figure.

Working Status of Interfaces 50 and 52

Figure 8: Working Status of Interfaces 50 and 52

4. Go over the DDM information to review whether the transceiver works in normal status.

DDM Information of Ports 50 and 52

Figure 9: DDM Information of Ports 50 and 52

Summary

To troubleshoot the circuit connectivity as well as the transceiver and the switch port, loopback test is a cost-effective way. In this post, we have an overview of loopback and make a demonstration of how to conduct the loopback test on a switch to debug the transceiver and the switch port.