Category Archives: DAC/AOC Cable

Decoding 25G Ethernet And Its Optics

Most us of us may quite familiar with 10G, 40G and 100G Ethernet network, but we know little about 25G Ethernet, or even never heard about it. In the race of 10G, 40G and 100G Ethernet, it seems that 25G Ethernet lagged far behind. However, it is a good choice for network connectivity indeed. So what is 25G Ethernet and its benefits? And what about its cables and optical modules? The detailed information about 25G Ethernet would be provided in this article.

Overview on 25G Ethernet

Researched and developed by IEEE group, 25G Gigabit Ethernet is a standard for Ethernet connectivity. Compared with 10G, 40G and 100G Ethernet, 25G and 50G Ethernet were the latest developed Ethernet specification. 25G Ethernet Consortium was formed in July 2014 to support the specification of single-lane 25G Ethernet. It is an open organization to all third parties who wish to participate as members to enable the transmission of Ethernet frames at 25 or 50 Gigabit per seconds (Gbps) and to promote the standardization and improvement of the interfaces for applicable products.

25G Ethernet Specification

Based on single lane 25 Gb/s technology, the Consortium standard provides specifications for implementation, enabling Ethernet users to deploy cost effective Ethernet technologies. It is a technology that aimed at using (a) one 25 Gb/s lane to connect a single MAC operating at 25 GB/s by means of a Clause 49 PCS. The following figure shows how 25 Gb/s ports can be enabled.

25G Single Lane

Figure1: 25Gb/s SerDes Single Lane

For the configurations shown in Figure 1, 25Gb/s interfaces represent themselves as networking ports. They can auto-negotiate link speed by proprietary bit locations in extended capabilities registers.

Features and advantages of 25G Ethernet
  • Technology
    25G Ethernet technology is designed for application and infrastructure efficiency that results in a better data center ROI.
  • Robustness and reliability
    The 25G Ethernet technology is robust and reliable, and the products of Ethernet 25G are deigned to the highest standards and built to last. Weakness in one area can cascade and cause challenges that impact the entire system design and limit product reliability. The consequences would be too ghastly to contemplate.
  • Performance
    Industry analysts are predicting that 25GbE Ethernet will have the fastest adoption ramp ever for a new Ethernet technology. To make this forecast a reality requires not only 25 GbE technology that is both manufacturable and offers better features and capabilities, but also provides a true performance advantage.
  • Ease of adoption
    The IEEE group and 25G Ethernet Consortium have worked hard to ensure that 25G Ethernet offers a seamless upgrade to 10G Ethernet environments, with backwards compatibility that use the same 10GbE LC fiber cabling that has already been deployed in the data center.
  • Price
    Although 25GbE Ethernet is slightly more expensive than the 10GbE pricing, it still delivers a reasonable price. In fact the 25GbE pricing is very competitive, with only a 30% to 40% premium over 10GbE, and this premium is expected to come down over time. Overall, 25G Ethernet still offers a cost-effective solution for network connectivity.
25G SFP28 Optics

In general, there are three kinds of SFP28 optics, 25G SFP28 AOC and DAC cables as well as 25G SFP28 transceivers.

25G SFP28 AOC and DAC cable

The 25G SFP28 active optical cable is designed to overcome the bandwidth limitation of traditional copper cable so as to meet the high bandwidth in data center. It is hot pluggable and preterminated twin axial cable/fiber cable. The transmission distance can be 70 m by active optical cable with OM3 fiber. It is applicable to 25G and 10G Ethernet, data center and in-rack connection. For SFP28 DAC cable, there are two types: 25G SFP28 to SFP28 DAC and 100G QSFP28 to four SFP28 breakout DAC. These copper cables provide a cost-effective solution for connection with Top of Rack switches.

25g-sfp28-active-optical-cable

Figure2: 25G SFP28 Active Optical Cable

25G SFP28 transceivers

Basically, there are two kinds of 25G SFP28 transceiver, 25G SFP28 SR and 25G SFP28 LR optical transceiver. The 25G SFP28 SR designed to transfer data over short distance while the 25G SFP28 LR transceiver set for long distance transmission. The maximum transmission length of 25G SFP28 SR is 100 m over 50μm multimode optical fiber. The transmission distance of 25G SFP28 LR optical transceiver can be up to 10 km over single-mode fiber. Both the transceivers can be applied to data center, 10G&25G Ethernet, high-speed storage area networks and in-rack connection.

SFP28-Transceiver

Figure3: 25G SFP28 Transceiver

Conclusion

25G Ethernet is taking off fast. It has a handful of very powerful data center and cloud vendors and suppliers-Google, Microsoft, Broadcom, Arista, Mellanox and Cisco. The 25G technology already exists in 100G will drive better cost efficiencies than 40G as well, saving cloud providers and enterprise data centers capital and operating expense. FS.COM provides large and in-stock 25G SFP+ cables and 25G SFP SR transceiver with high quality but low cost. If you are interested with our products, please feel free to contact us.

How to Connect Optics for Arista 7250QX-64 Switch

In the previous post “Compatible Optics for Arista-7250QX-64“, we are clear that the features and compatible direct attach cables and optical modules of the Arista 7250QX-64 switch. But how to make the right connection? Is there anything to notice before and in the process of installation? This article would provide a satisfying solution for you.

Connecting a QSFP+ DAC Cable to Arista 7250QX-64

The proper connectivity procedures and some installation notes are very essential for connection between DAC cable and the switch. The detailed information are just below.

The connectivity steps:

1. If the QSFP+ DAC cable connector is covered with a rubber safety cap, remove the cap. Save the cap.
2. Check the port on the switch and make sure the right connectivity. If you choose 40G QSFP+ to QSFP+ DAC cable for connectivity, please make sure that is a 40G port.
3. Insert the cable connector into the switch port.

DAC cable to switch-connection

Figure1: Connecting a DAC cable to a switch

4. Secure the cables so that they do not support their own weight. Place excess cable out of the way in a neatly coiled loop. Placing fasteners on a loop helps cables maintain their shape.

Warnings and Cautions

1. Before you begin connecting the QSFP+ DAC cables to the switch, ensure that you have taken the necessary precautions for safe handling of lasers.
2. Do not bend the QSFP+ DAC cables beyond their minimum bend radius. An arc smaller than a few inches in diameter can damage the cables and cause problems that are difficult to diagnose.
3. Do not let the DAC cables hang free from the connector.
4. Do not allow fastened loops of cables to dangle, which stress the cables at the fastening point.

Installing a QSFP+ transceiver in Arista 7250QX-64

There are many QSFP+ transceiver types supporting Arista 7250QX-64, including QSFP-40G-SR4, QSFP-40G-XSR4, QSFP-40G-PLRL4, QSFP-40G-LRL4, QSFP-40G-PLR4, QSFP-40G-LR4, and QSFP-40G-ER4. Before you begin installing one QSFP+ transceiver in an Arista 7250QX-64 switch, ensure that you have a rubber safety cap available to cover the transceiver. And to prevent electrostatic discharge (ESD) damage to the transceiver, do not touch the connector pins at the ends the transceiver. Figure 2 shows how to install a QSFP+ transceiver.

Optical transceiver-switch connection

Figure 2: installing a QSFP+ transceiver in a switch

Installation steps:

1. Remove the transceiver from its bag.
2. Check to see whether the transceiver is covered with a rubber safety cap. If it is not, cover the transceiver with a rubber safety cap.
Warning: Do not leave a QSFP+ transceiver uncovered except when inserting or removing a cable. The rubber safety cap keeps the port clean and prevents accidental exposure to laser light.
3. If the port in which you want to install the transceiver is covered with a dust cover, remove the dust cover and save it in case you need to cover the port later. If you are hot-swapping a transceiver, wait for at least 10 seconds after removing the transceiver from the port before installing a new transceiver.
4. Using both hands, carefully place the transceiver in the empty port. The connectors must face the switch chassis.
Caution: Before you slide the transceiver into the port, ensure that the transceiver us aligned correctly. Misalignment might cause the pins to bend, making the transceiver unusable.
5. Slide the transceiver in gently until it is fully seated.
6. Remove the rubber safety cap when you are ready to connect the cable to the transceiver.

Summary

From the above passage, we may observe that it is not difficult to connect QSFP+ DAC cables or QSFP+ transceiver to the Arista 7250QX-64 switch. Whether you are using DAC cables or QSFP+ transceivers to make connectivity, please remember that do not look directly into a optical transceiver or into the ends of the DAC cables, the laser light may damage your eyes. FS.COM offers large and in-stock Arista 40G QSFP+ DAC cables as well as 40G QSFP+ optical transceivers. If you need any of our products, please feel free to contact us.

Compatible Optics for Arista 7250QX-64

In order to meet the ever-growing need for dense 10 and 40 Gigabit Ethernet switching, Arista launches the 7250X Series switches to support a flexible combination of 10G and 40G in a compact form factor to accommodate both east-west traffic patterns and support the requirement for low latency and power efficiency in dense servers farms. Among the 7250X Series, the Arista 7250QX-64 switch has been highly favored by many Ethernet users due to its low latency, high power efficiency and high performance. The detailed information about the Arista 7250QX-64 switch and its compatible optics will be mainly covered in the following passage.

Features of Arista 7250QX-64

The Arista 7250QX-64 combines low latency, and a shared packet buffer pool of 12MB per group of ports that is allocated dynamically to ports that are congested. With 64 QSFP+ ports the 7250QX-64 is a dense 40GbE or 256 × 10GbE of wire speed performance in a 2RU system. Here are some highlights of this switch:

  • Built-in storage.
  • Resilient control plane.
  • Cloud networking ready.
  • Data center optimized design.

Arista 7250QX-64

The above figure shows Arista 7250QX-64 switch’s 64 QSFP+ ports supporting 64 × 40GbE or 256 × 10GbE.

Compatible Optics for Arista 7250QX-64 at FS.COM

The Arista 7250QX-64 supports a full rang of 10 and 40 Gigabit Ethernet connectivity options. Those 10G/40G ports support installation of SFP+ and QSFP+ modules. FS.COM provides many high-quality compatible 40G QSFP+ DAC cables and 40G QSFP+ modules for Arista 7250QX-64. You can see it clearly in the following tables.

40G QSFP+ Direct Attach Cables
Description of 40G QSFP+ DAC

From the above statement, we are clear that the Arista 7250QX-64 switch has 64 QSFP+ ports, so you can directly connect “transceivers” on the two ends of the DAC cables to the corresponding port on the switch. For transmission distance over short distance, you can choose 40G QSFP+ DAC cables to make network connectivity. By using 40G breakout cable, you can just plug the one end of 40G QSFP+ copper direct attach cable into the 40G QSFP+ ports and plug the other ends of the DAC cable into four 10G SFP+ ports. Besides, you can also connect the two ends of 40G QSFP+ DAC cable with the 40G QSFP+ ports directly to make connectivity on the Arista 7250QX-64 switch. When the transmission distance is longer, 40G QSFP+ AOC cable is a good option to transfer data. Like the 40G QSFP+ DAC cable, you can plug the two ends of 40G QSFP+ AOC cable into the QSFP+ ports on the Arista 7250QX-64 switch. Those 40G QSFP+ DAC and AOC cables are suitable for short distance and ideal for high cost-effective connectivity to your Arista 7250QX-64 switch.

40G QSFP+ Optical Transceivers

As we can see from the above figure, there are many 40G QSFP+ modules available to the Arista 7250QX-64 switch. By using 40GBASE-SR4 QSFP+ transceiver, the maximum distance can be up to 40 km via single-mode fiber on the switch. Through 40GBASE-XSR4 QSFP+ module, link lengths on 7250QX-64 switch can arrive 300 m and 400 m, respectively, on laser-optimized OM3 and OM4 multimode fibers. FS.COM offers the above 40G QSFP+ optical transceivers, which is of compatibility and performance. In addition, all of FS.COM’s optical transceiver are tested for 100% functionality and guaranteed compatible for outstanding network performance.

Summary

The Arista 7250QX-64 is designed for high availability, low latency and high power efficiency, which provides a better solution for 10G/40G Ethernet network connectivity. FS.COM offers large and in-stock Arista 40G QSFP+ DAC cables as well as 40G QSFP+ optical transceivers with low cost but high quality. Besides, our products are free shopping right now in USA, Canada and Mexico. If you need any of our products, please feel free to contact us.

Compatible DAC Cables for HPE 7510 Switch

In order to meet the evolving needs of integrated services networks, HPE launches a series of HPE FlexNetwork 7500 switches. They offer 40GbE connectivity and cost effective, wire-speed 10GbE ports to safeguard the throughput and bandwidth needed for mission-critical data and high-speed communications. The HPE FlexNetwork 7500 switches have three specifications: HPE FlexNetwork 7510 Switch, HPE FlexNetwork 7506 Switch and HPE FlexNetwork 7503 Switch. Among them, HPE FlexNetwork 7510 Switch is of popularity and highly favored by many Ethernet users. Today, we would mainly introduce the features of HPE 7510 switch and its compatible DAC cables.

Overview on HPE 7510 Switch

HPE 7510 Switch (JH333A) offers 10GbE and 40GbE connectivity. And it delivers wire-speed Layer 2 and Layer 3 routing services as well. HPE 7510 Switch is a 12-slot horizontal chassis of 16U, with ten I/O module slots support a maximum of 480 Gigabit Ethernet port SFP+ and two port 40GbE QSFP+ main processing units. The I/O module slots support a maximum of 480 Gigabit Ethernet ports or 480 autosensing 10/100/1000 ports or 160 × 1/10GbE ports or 80 × 10GbE posts or 40 × 40GbE ports, or a combination. Among the series of HPE FlexNetwork 7500 switches, JH333A has several distinctive features:

  • It uses an access controls list (ACL) to enforce increased bandwidth for ingress traffic on each port.
  • Industry-standard CLI with a hierarchical structure. Reduces training time and expenses; and increases productivity in multivendor installations.
  • Signature update service. It provides regular updates to the signature database, helping ensure that the latest available signatures are installed.
  • Management interface control. It provides management access through a modern port and terminal interface.

HPE 7510 Switch

This HPE FlexNetwork 7510 Switch supports a maximum of 480 PoE/PoE+ ports, 480 Gigabit Ethernet ports or 480 autosensing 10/100/1000 ports or 480 1/10GbE ports or 480 10GbE ports or 44 40GbE ports or a combination.

Compatible DAC Cables for HEP 7510 Switch

The HEP 7510 switch supports a full rang of 10 and 40 Gigabit Ethernet connectivity options. Those 10G/40G ports support installation of SFP+ and QSFP+ optical modules as well as 10G and 40G direct attach cables for HEP 7510 switch. We would mainly focus on its compatible direct attach cables in the following part.

10G SFP+ Direct Attach Cables
Description of 10G SFP+ DAC Cable

From the last paragraph, we figure out that the HEP 7510 switch has 10G SFP+ ports, so you can directly plug one end of the 10G SFP+ “transceiver” of 10G SFP+ DAC cable into the SFP+ ports on the switch. As we can see from the above table, HEP 7510 switch supports 0.65 m, 1.2 m, 3 m and 5 m long SFP+ passive DAC cables. These cables are hot-removable and hot-insertable: You can remove and replace them without powering off the switch or disrupting switch functions. The cables use high-performance integrated duplex serial data links for bidirectional communication and the maximum data rates can be up to 10Gbps on this HEP 7510 switch connecting with 10 Gigabit Ethernet port. The above HEP SFP+ DAC cables are suitable for in-rack connections between server and HEP 7510 Switch. They are suitable for short distances and ideal for high cost-effective connectivity to your HEP switch.

40G QSFP+ Direct Attach Cables
Description of 40G QSFP+ DAC Cable

The HEP 7510 switch are fixed switch built to provide 10Gbps and 40Gbps server access connectivity. From the above statement, we are clear that the HEP 7510 switch has both 10G SFP+ and 40G QSFP+ ports. Thus, you can connect the end of 40G QSFP+ “transceiver” of 40G QSFP+ DAC cable with the 40G QSFP+ ports directly to make connectivity on the HEP 7510 switch. And also, you can use 40G QSFP+ to 4SFP+ DAC cable to connect—you can just plug the one end of 40G QSFP+ “transceiver” into the 40G QSFP+ ports and plug the other four 10G SFP+ “transceivers” on the other end into the 10G SFP+ ports. The QSFP+ “transceiver” connects directly into the QSFP+ access port on the HEP 7510 Switch with a data rate of 40Gbps while the other end with 4 SFP+ “transceivers” can arrive a data rate of 10Gbps each. The cables use high-performance integrated duplex serial data links for bidirectional communication on four links simultaneously. 40G QSFP+ passive DAC cables are suitable for very short distances and provide a simple and useful way to establish a 40G link between QSFP+ ports switches within racks and acrossadjacent racks.

Summary

HPE 7510 (JH333A) switch is a high performance switch, which can be deployed in the enterprise LAN core, aggregation layer, and wiring closet edge. If you are looking for its compatible optical modules and cables, FS.COM is an optimal option as it provides large and in-stock the optical modules and direct attach cables for the HPE 7510 switch with low cost but high quality. Recently, our products are free shipping in USA, Canada and Mexico. If you need any of our products, please feel free to contact us.