Stackable 10Gbase-T Switch or Standalone 10Gbase-T Switch, Which One Is Better?

When searching for a 10Gbase-T switch, you may find some switches are labeled as stackable managed switch. What does stackable switch mean? What’s the difference between standalone 10Gbase-T switch and stackable 10Gbase-T switch? What kind of switch should choose? Don’t worry. Keep reading this article.

What Is Stackable Switch?

Stackable switch means a network switch can be set up in a group to work with one or other switches. These switches are combined through connecting certain ports. Stackable switch can also operate as a standalone switch.

One thing you should notice is that “clustering” is not as the same as “stackable”. Though some switches appear in a single unit, actually these are “clustering switches” and must be managed and configured individually. They don’t have any stacking capability which allow you to configure, manage and troubleshoot all switches in a stack as a single unit.

Should We Buy Stackable 10Gbase-T Switch or Standalone 10Gbase-T Switch?

Switch is the most important device to receive, process and transmit data information in a network. At the same time, 10Gbase-T switch is not cheap. Buying an inappropriate switch not only influences network data quality but also leads to cost waste. To select a stackable 10Gbase-T switch or a standalone 10Gbase-T switch, we should know advantages and disadvantages of each switch before making decisions.

Stackable Switches Features

Some business choose to install stackable switches because of their advantages, for instance, simplicity, scalability, and flexibility. Since stackable switches work as one single switch, it’s easier to manage and set up the network. If we need to add more ports to current network, we can simply buy another stackable switch and add it to the stack. Although stackable switches have so many advantages, they still have some disadvantages. First, when one of stackable switches stops working, cable connections would fail and these cables should be reset or replaced. Therefore, we have to bring down the entire stack. Second, when lots of data transmitting over these switches in a stack, the speed of the stack ports and the ring architecture of the stack can cause bad influences.

Standalone Switches Features

Standalone switches don’t have stacking ports, so they can’t be connected together to work like a single switch. That causes inconvenience to scale because we have to connect each switch to the distribution layer. For larger deployments, it would cost more. But standalone switches work well in small server room or data center.

Recommendation of Standalone 10Gbase-T Switch and Stackable 10Gbase-T Switch

In a small campus deployment or data center with limited space, standalone switches are popular as top-of-rack switches. Here is a standalone 10Gbase-T switch. S5850-48T4Q switch supports 48 10Gbase-T ports and 4 40G QSFP+ ports. It’s designed to be applied in Enterprise, Data Center and Metro network. To know more details about this switch, you can also read this article.

10gbase-t-switch-S5850-48T4Q

Unlike standalone switch, stackable switches work in different environments. As mentioned above, stackable switches can be combined into one single unit. So if you need to scale network, you can choose stackable switches which is more helpful to manage and troubleshoot. Well, I’d like to recommend another 48-port 10Gbase-T switch to you. Cisco SG350XG-48T is one of Cisco 350X series switches which are truly stackable. It has two combo ports, one for copper and one for fiber. This switch can be stacked up to 4 units, 192 10Gbase-T ports in one single unit. When combining switches into a stack, don’t just connect all these devices. Remember to make the stack work normally. It’s not easy to match all stackable switches. If you don’t know how, you should follow experts’ guidelines to do the configuration.

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10GBase-T Switch Recommendations

10 Gigabit Ethernet network is popular in data center now. 10GbE interfaces mainly include SFP+, SFP+ direct attach cable, and 10GBase-T. Most data centers choose connection of SFP+ and SFP+ DAC. As 10GBase-T offers benefits of improved bandwidth, increased flexibility, infrastructure simplification, cost reduction, 10GBase-T interface is more and more widely used. To build 10Gbase-T connection, you need an indispensable equipment- 10GBase-T switch. As some are confused about choosing 10GBase-T switch, this article will recommend several 10GBase-T switches and hope that can help you.

10GBASE-T Switch Recommendation 1–Cisco Nexus 5596T Switch

Cisco plays a leading role in optical communication industry. Cisco switch is famous for its high quality and is always the first choice of some data centers. Cisco Nexus 5596T switch is one of Cisco 10Gbase-T switch. Let’s get a close look at it.

Cisco Nexus 5596T switch has 96 ports, including 32 fixed 10Gbase-T ports and 16 fixed SFP+ ports in a compact 2RU form factor. It’s configured with three expansion modules which can be used to increase the number of 10Gigabit Ethernet, FCOE ports, Unified Ports, or to connect to 1/2/4/8 native Fibre Channel ports. Throughput of Cisco Nexus 5596T Switch can reach up to 1.92 Tbps. With Cisco Nexus 5596T switch you can enjoy the benefits of 10GBASE-T technology and its simplicity, speed, and design flexibility.

10GBASE-T Switch Recommendation 2–Arista Networks 7050T-64 Switch

Arista 7050T-64 10Gbase-T switch is one of Arista 7050TX series, which show obvious advantages in performance, scale and power efficiency in fixed 10G data center switches. The 7050T-64 switch offers 48 auto-negotiating 1Gb/10GBase-T ports with standard RJ45 interfaces and 4x40G QSFP+ ports. Each QSFP+ port can operate as four independent 10G ports to provide 64 10G interfaces. As data center server access, 7050T-64 switch offers backwards compatibility with existing standard Gigabit Ethernet cabling and saves cost on migration to 10 Gigabit Ethernet.

10GBASE-T Switch Recommendation 3–FS S5850-48T4Q Switch

S5850-48T4Q switch, offered by FS.COM (Fiberstore), is a high performance Ethernet switch applicable Metro, Data Center and Enterprise network. This switch has 48 10Gbase-T ports with standard R45 interfaces and 4x40GbE QSFP+ ports in a compact 1RU form factor. It supports operating rates of 1Gbit/s, 10 Gbit/s, 40 Gbit/s, 100Gbit/s and auto-negotiation. The S5850-48T4Q comes with complete system software with comprehensive protocols and applications to facilitate rapid service deployment and management for both traditional layer2/3 networks and Data Center networks. S5850-48T4Q 10Gbase-T switch stands out because of many advantages. With pluggable redundant fans and power supply, it supports 1+1 redundancy. And the temperature and status of fans and power supply can be real-time monitored by the system. The fan supports intelligent speed control function, green and energy-saving. This is a low power consumption and low latency 10Gbase-T switch.

FS-10Gbase-T-switch

Comparison of Cisco & Arista & FS 10Gbase-T Switches

From switch appearance, these switches has different numbers of 10Gbase-T ports. From switch property, Cisco Nexus 5596T switch and Arista 7050T-64 10Gbase-T switch are traditional switches while FS S5850-48T4Q switch is OpenFlow/SDN (Software Defined Network) switch. What is SDN switch and what is the difference? You may be not very clear about this. An SDN switch is a software program or hardware device that forwards packets in a software-defined networking (SDN) environment. This kind of switch separates the data plane from the control plane. The data plane is implemented in the switch but the control plane is implemented in software and a separate SDN controller makes high-level routing decisions. The switch and SDN controller communicate by OpenFlow protocol. However, in a traditional switch, packet forwarding and high level routing are implemented in a same device. Another difference that can’t be ignored is the price. Cisco Nexus 5596T switch is about $40,500. Arista 7050T-64 is about $15,829.64. And FS S5850-48T4Q switch $4,599.

I have recommended three 10Gbase-T switches in this article, traditional or SDN switch, expensive or cheap type. By the comparison above, you can decide which one you’ll choose. More conveniences, here I recommend 10Gbase-t SFP+ transceivers for your 10Gbase-T switches.

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VXLAN vs VLAN: Which Is the Best Fit for Cloud Data Center?

Traditional VLAN links have been proven insufficient to cope with rigid requirements of cloud providers – as they are reaping significant benefits by stretching Layer 2 over Layer 3 network to build large multitenant data centers. VXLAN (Virtual Extensible Local Area Network) technology is proposed to extend VLAN and overcome the limited scalability posed by VLAN. The VXLAN provides layer 2 connectivity extension across the layer 3 boundary, enabling large-scale virtualized and multitenant data center designs over a shared common physical infrastructure. This article sticks to the basics of VXLAN and the difference between VXLAN vs VLAN.

VXLAN vs VLAN: A Quick Overview

VXLAN is a network virtualization scheme that enables users to create a logical network for virtual machines (VMs) across different networks. That is to say, it allows you to create a layer 2 network on top of layer 3 through encapsulation. What to emphasize is that you could potentially create 16 million networks using VXLAN, compared to the 4096 VLANs. In this case, VXLAN technology enables network to support far more VLANs. As a result, more logical network isolation for large networks can house much more virtual machines.

VXLAN vs VLAN

VXLAN vs VLAN: Why Choose VXLAN Instead of VLAN?

VXLAN allows you to create smaller layer 2 domains that are connected over a layer 3 network. Which eliminates the need to use Spanning Tree Protocol (STP) to converge the topology – but with a more robust routing protocols in the layer 3 network. Without STP, none of your links are blocked, so you can obtain full value from all the ports you purchased. VXLAN also enables you to load-balance the traffic to get the best use of your available bandwidth. These all makes sense to maximize data center performance.

VXLAN for cloud data center

VXLAN makes a dramatic difference for building cloud data centers. It lays the foundation of a scalable cloud network – where lots of logical networks can be created in a timely manner. This therefore satisfies the needs of the most complex and dynamic cloud. VXLAN, in fact, has successfully pushed the boundary of virtual machine migration beyond layer 2 domain.

VXLAN Technology: How to Understand it?

VXLAN uses Layer 3 multicast to support the transmission of multicast and broadcast traffic in the virtual network, while decoupling the virtual network from the physical infrastructure. In this environment, a VXLAN gateway device can be used to terminate the VXLAN tunnel and forward traffic to and from a physical network. Here are explanations assist in understanding VXLAN.

VLAN-VTEP

VXLAN gateway: A VXLAN gateway bridges traffic between VXLAN and non-VXLAN environments by becoming a virtual network endpoint. For example, it can link a traditional VLAN and a VXLAN network,

VXLAN segment: A VXLAN segment is a Layer 2 overlay network over which VMs communicate. Only VMs within the same VXLAN segment can communicate with each other.

VNI: The Virtual Network Identifier (VNI), also referred to as VXLAN segment ID. The system uses the VNI, along with the VLAN ID, to identify the appropriate tunnel.

VTEP: The VXLAN Tunnel Endpoint (VTEP) terminates a VXLAN tunnel. The same local IP address can be used for multiple tunnels.

VXLAN header: In addition to the UDP header, encapsulated packages include a VXLAN header, which carries a 24-bit VNI to uniquely identify Layer 2 segments within the overlay.

VXLAN vs VLAN: What Are the Advantages?

VXLAN is developed to provide the same Ethernet Layer 2 network services as VLAN does today, but with greater extensibility and flexibility. When it comes to segment your networks, VXLAN functions just like VLAN and possesses advantages VLAN don’t have. Here are the most significant benefits of using VXLANs.

  • You can theoretically create as many as 16 million VXLANs in an administrative domain, as opposed to 4094 VLANs.
  • VM can migrate between servers that exist in separate Layer 2 domains by tunneling the traffic over Layer 3 networks. So you can dynamically allocate resources within or between data centers without being constraint by Layer 3 boundaries.
  • Flexible placement of multitenant segments: VXLAN extends Layer 2 segments over the underlying shared network infrastructure so that tenant workload can be placed across physical pods.
  • Higher scalability to address more layer 2 segments: VXLAN uses a 24-bit segment ID, also known as the VXLAN network identifier (VNID), which enables up to 16 million VXLAN segments to coexist in the same administrative domain.
  • Better utilization of available network paths in the underlying infrastructure: VXLAN packets are transferred through the underlying network based on its Layer 3 header and can take complete advantages of Layer 3 routing and link aggregation protocols to use all available paths.
VXLAN: the Trend of Future Network

When compared VXLAN vs VLAN, VXLAN is no doubt a better solution with evident benefits: sufficient links and capacity to handle massive traffic in cloud environment. VXLAN technology is meant to provide same services connected to Ethernet end systems that VLANs do today, while offer a means to stretch L2 network over a L3 network. VXLAN assures clean isolation between VMs and physical IP-based transport infrastructure, and enables unsurpassed reliability and scalability to network. Just remember that we need VXLAN termination in physical devices, such as switches, firewalls and load balancers before we can start considering large-scale deployments.

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Cisco FEX: Extending the Boundaries of Data Center Fabric

Cisco FEX, or Fabric Extender technology makes the central part of Cisco’s data center strategy. With its Nexus 2000 FEXes as the representative, Cisco FEX functions to extend the switching fabric of the core and aggregated switches – Nexus 5000/7000 series switches. FEX, as a matter of fact, can be regarded as a remote line card with no local switching capabilities. This article focus on explaining the functions of Cisco FEX, and how it helps extend data center fabric.

Cisco FEX: Extends Beyond Edge Devices

A Cisco FEX is a companion to a Nexus 5000 or Nexus 7000 switch. That’s to say, when being connected to them, FEX thus become a logical part of the parent switch. A Cisco FEX has no management interface and has no capability to store a forwarding table or run any control plane protocols. Instead, it relies on its parent N5000/7000 to perform those functions. As the name indicates, Cisco FEX “extends” the fabric out towards the edge devices that require network connectivity. The three major parts in this fabric extension are shown in the following picture: central switch (i.e. N5000/7000), external backplane and remote line card (N2000).

Cisco-FEX-component

Cisco FEX: What Are the Benefits?

For data centers that have deployed Cisco Nexus 5000 or 7000 switches, Cisco Nexus 2000 series FEX are commonly used for top of rack (ToR) connectivity. These FEXes are usually attractive in price, as they are with a limited purpose and features. Cisco FEX even cannot be considered as a switch, because it cannot switch traffic locally or be managed independently. However, it significantly simplifies data center access architecture and operation when working with the parent switch. The benefits Cisco N2000 FEX delivers to data center can be summarized as follows:

  • With flexible and simplified top-of-rack designs, it streamlines management and centralized configuration.
  • Multiple parent switch support – N5K, N6K, N7K, N9K, and unified ports provide flexible LAN and SAN deployment
  • Cisco FEXes are fully managed as part of the parent switch and do not require independent software upgrades, configuration backups, or other maintenance tasks.
  • They are able to leverage Virtual Port Channels for connecting to redundant parent switches thereby eliminating Spanning Tree and enabling active to active uplinks.
  • Concerning the reduced OPEX and CAPEX, Cisco FEXes contribute largely to lower TCO. Thus offer a more cost effective alternative than an equivalent switch.
Cisco FEX Design and Topology

Cisco FEX features agility, flexibility, and simplicity at scale, which can be integrates into existing network infrastructures as well as Cisco Application Centric Infrastructure (Cisco ACI). As mentioned, just think of Cisco FEX like a remote line card that connected to the parent switch –but with no ability to make forwarding decisions on its own. The parent switches just like the supervisor which manages the cards, runs the control and management planes, and also makes the data plane forwarding decisions. Connection from FEX to parent switch is done via SFP module with fiber, or a DAC twinax cable, then physically spread throughout the data center. Depending on the FEX model, there are two or four SFP uplinks possible.

The following picture demonstrates a common topology of fabric extension in data center.

Cisco-FEX-design-configuration

Conclusion

Cisco FEX acts as a remote I/O module or virtual line card of Nexus 5K/7K, while offering an agile connectivity for rack and blade servers and for converged fabric deployments. It delivers innovation to the data center, reduces total cost of ownership and gains architectural flexibility. It is worth to consider Cisco FEX to extending your data center fabric, concerning the simplified management and maintenance it brings. Like always I hope this post is helpful to grasp more information about Cisco FEX technologies.

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QSFP-DD vs OSFP: The Wave of the Future 400G Transceiver

Over the past years, the discussion of 200G and 400G Ethernet speeds started heating up among data center professionals. The next station for IT community is 400G. And two standards organizations have been working behind the scenes with this benchmark for the past couple years, and in 2016 the long-awaited public launch of efforts to develop QSFP-DD and OSFP optical transceiver modules for 400-Gbps applications had finally arrived. Although 400G Ethernet is not the mainstream now, but we can still not deny the fact that it will finally become the mainstream in the near future. And QSFP-DD vs OSFP optical transceiver will be the top trend for future transceiver.

Introduction to QSFP-DD

QSFP-DD refers to Quad Small Form Factor Pluggable Double Density.  We know that current QSFP28 optical modules support 40 and 100 Gigabit Ethernet applications. They feature four electrical lanes that can operate at 10 or 25 Gbps. While the new QSFP-DD is designed with eight lanes that operate at up to 25 Gbps via NRZ modulation or 50 Gbps via PAM4 modulation, which would support optical transmission of 200 Gbps or 400 Gbps aggregate, thus doubling the density. At the 400G transmission rate, the QSFP-DD form factor could enable up to 14.4 Tbps aggregate bandwidth in a single switch slot so as to cope with rapid data center traffic growth. Another greatest advantage of this new generation of QSFP is its backward compatibility with the QSFP and QSFP28.

Introduction to QSFP-DD

Introduction to OSFP

OSFP stands for Octal Small Formfactor Pluggable, which is a very new module and interconnect system in development that is targeted to support 400G optical data links inside data centers, campuses and external metro long reach. OSFP’s first iteration is an 8-lane times 50G PAM4 = 400G physical link with a possible future 4 x100G PAM4 = 400G and 8 lanes times 100G PAM4 = 800G variants. This physical packaging system is agnostic relative to the different protocol I/O interfaces that will likely use it. The OSFP module or cable plug is a dual paddleboard direct-attachment type connection. This form factor allows 32 400 Gb/s ports per 1U to enable 12.8 Tb/s per switch slot. And the OSFP to QSFP+ adapters will support backward compatibility between form factors.

Introduction to OSFP

400G QSFP-DD vs OSFP: Who Will Win?

OSFP’s module size is said to be slightly wider and deeper than the QSFP-DD module, thus taking up more PCB surface area. Several OSFP modules on a line card use much more area and only 32 ports per 1U box faceplate are possible versus the 36 ports of QSFP-DD. The larger size OSFP may not have enough power and cooling advantages versus QSFP-DD’s density and its four extra port capability. Different users with different applications may fervently prefer one connection system versus the other relative to their panel density, cost, performance, power and cooling priorities. And according to the market forecast, the QSFP-DD should be ready before the OSFP, which is another advantage in addition to its backward compatibility with QSFP and QSFP28. As it has been mentioned, OSFP will need an adapter to support backward compatibility between form factors. It seems that the future for QSFP-DD is brighter. But now it is still too early to draw the conclusion and the two modules will have slightly different applications .

Summary

Although many data centers are still upgrading their network to a 100G data rate thanks to the cost-effective and high performance, 400G optical transceivers, as the wave of the future transceiver, are already on the way. As for the question: 400G QSFP-DD vs OSFP: Who Will Win? Let’s wait and see!

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