Core Switch Vs Distribution Switch Vs Access Switch

The hierarchical internetworking model defined by Cisco includes core layer, distribution layer and access layer. Therefore, the network switches working in these layers get corresponding names like core switch, distribution switch and access switch. This post mainly explores the confusing problem: core switch vs distribution switch vs access switch.

Definition: Core Switch Vs Distribution Switch Vs Access Switch

What Is Core Switch?

Core switch is not a certain kind of network switch. It refers to the data switch that is positioned at the backbone or physical core of a network. Therefore, it must be a high-capacity switch so as to serve as the gateway to a wide area network (WAN) or the Internet. In a word, it provides the final aggregation point for the network and allows various aggregation modules to work together.

What Is Distribution Switch?

Similarly, the distribution switch lies in distribution layer, and it links upwards to layer core switch and downwards to the access switch. It is also called aggregation switch which functions as a bridge between core layer switch and access layer switch. In addition, distribution switch ensures that the packets are appropriately routed between subnets and VLANs in enterprise network. 10gb switch usually can perform as a distribution switch.

What Is Access Switch?

Access switch generally locates at the access layer for connecting the majority of devices to the network, therefore it usually has high-density ports. It is the most commonly-used gigabit Ethernet switch which communicates directly with the public Internet, mostly used in offices, small server rooms, and media production centers. Both managed and unmanaged switches can be deployed as access layer switch.

core switch vs distribution switch vs access switch

Figure 1: core switch vs distribution switch vs access switch

Comparison: Core Switch Vs Distribution Switch Vs Access Switch

The switches may co-exist in the same network, and coordinate with each other to contribute to an unrestricted network speed with each layer switch performing its own duty. Well, what’s the difference: core switch vs distribution switch vs access switch?

Core Switch Vs Distribution Switch

Core switch has the higher reliability, functionality and throughput than distribution switch. The former one aims at routing and forwarding, and provides optimized and reliable backbone transmission structure, while the latter one functions as the unified exit for access node, and may also do routing and forwarding. The distribution switch must has large enough capacity to process all traffic from the access devices. What’s more, there’s generally only one (or two for redundancy) core switch used in a small and midsize network, but multiple distribution switches in distribution or aggregation layer.

Core Switch Vs Access Switch

The lower levels the switch dwells in, the more devices it connects to. Therefore, a big gap of ports number exists in access switch and core switch. Most access switches need to connect various end user equipment ranging from IP phone, to PCs, cameras etc,. While the core switch may be just linked with several distribution switches. Meanwhile, the higher layer the switch lies in, the faster port speed it requires. Access switch is to core switch what river is to the ocean, as the latter one has the large throughput to receive the data packets from the former one. Most modern access switches come with a 10/100/1000Mbps copper ports. An example of this is FS S2800-24T4F 24 port 100/1000BASE-T copper gigabit Ethernet switch. While core switches commonly have 10Gbps and 100Gbps fiber optic ports.

Distribution Switch Vs Access Switch

As access switch is the one that allows your devices to connect the network, it undoubtedly supports port security, VLANs, Fast Ethernet/Gigabit Ethernet and etc. Distribution switch which is mainly responsible for routing and policy-based network connectivity supports additional higher performance like packet filtering, QoS, and application gateways. All in all, access switch is usually a layer 2 switch and distribution switch is a layer 3 switch. When multiple access switches among different VLANs are required to be aggregated, a distribution switch can achieve inter-VLAN communication.

Conclusion

What’s the difference: core switch vs distribution switch vs access switch. To sum up, the access switch facilitates devices to the network. The distribution switch accepts traffic from all the access layer switches and supports more high-end features. And the core switch is responsible for routing and forwarding at the highest level. FS provides different types of Ethernet switches that can work as core switches, distribution switch or access switches. For more details, please visit www.fs.com.

Network Switch Before or After Router?

Network switch and router are the commonly used devices in a network. With each carrying out its own duties accordingly, you can surf on the internet freely with your smart phone or computer. How to setup a network switch and router? Should the network switch be installed before router or after router is puzzling for many network newbies.

What Is Network Switch and Router?

To get clear about how to connect wireless router to switch, this part will state the function of network switch and router first. What is a switch in networking? A network switch is used to connect multiple devices such as computers, printers, IP camera and modem on the same network within a building. In this way, these devices can share information and communicate with each other.

What is a router in networking? A router is sometimes connected to a modem at one side and many other devices on the other side. Because the modem will only talk to the first computer that talks to it, the router at the position serves like a dispatcher to share the connection among all your devices. This enables all connected computers to share one single Internet connection.

Home network switch and router

Fig1. Home network diagram with switch and router

How to Setup a Network Switch and Router?

From the above introduction, we know that both the network switch and the router can be connected directly to a modem. However, when the two devices coexist, how to deploy them. Shall I connect modem to router to switch or modem to switch to router?

Modem to Router to Switch: Network Switch After Router

In most cases, you will see people put the modem first, followed by a router and then a gigabit Ethernet switch. The principle is that the modem gives the public IP address to the router, and the router assigns the private addresses to the devices connected to it, while the network switch doesn’t handle allocating IP addresses but serves as the extension of the limited ports on the router, to receive more devices. In this scenario, all your devices with private addresses are safe as they are not directly visible to the internet.

modem to router to network switch

Fig2. Modem router switch diagram

Modem to Switch to Router: Network Switch Before Router

Some people propose going from a cable modem to switch to wireless router. This seems good because all your devices on the network switch will have direct connections to your ISP. However, the truth is, your ISP does not offer multiple public IP addresses before the full transition from IPv4 to IPv6. So one or all ISP connections will likely fail and all of the devices connected to the switch would be exposed to the internet.

In a word, placing a modem to switch to router is not possible. At least not practically. Each port on the switch is a different IP address. So it doesn’t exist? Probably not unless your modem integrates the function of a router so that you can rewire and reconfigure the wireless router to set it up as access point. Seen from the outside, you indeed put a managed switch before router, however it still follows the principle that router goes before network switch.

Conclusion

Network switch before router or after router? Have you made it clear? This post has stated modem to router to switch vs modem to switch to router. Hope when you set up your network with router and switch, you can put them in the correct order according to your needs and the products themselves (the modem type). Here at FS.COM you can find various network switches including 10 gigabit switch, 40 gigabit switch and 100 gigabit switch, etc.

Core Switch vs Normal Switch: What Is the Difference?

In enterprise network, network switch is always an indispensable component. Thus locating right switches in your three-layer architecture is the first step to set up a reliable hierarchical internetworking model. As we know, there are normal access/edge layer switch, aggregation/distribution layer switch and core layer switch. In my last post – What Is Distribution Switch and Why Do We Need it? – the role of distribution switch functioning multiple switch aggregation and inter-VLAN routing has been illustrated. Today we will introduce core switch and what’s the difference between core switch vs normal switch.

What Is Core Switch?

Core switch occupies in the topside layer of the enterprise networking (core layer), which functions as backbone switch for LAN access and centralizes multiple aggregation to the core. Since other 2 lower layers rely upon it, core layer switch must be a highly redundant and powerful layer 3 switch to ensure efficient high-speed and reliable data transmission. One feature on its hardware is that core switch is often a fiber switch to match with high-speed fiber optic cables and fiber optic transceiver modules. In the core layer, switching is ending and routing is beginning. Core switch is also equipped with layer 3 routing features, thus it kills two birds with one stone.

Core switch normal port speed is at least 10Gbps to handle high traffic on the uplink. Say FS S5900-24S 24 Port 10GE SFP+ stackable managed switch. This fully managed fiber 10GbE switch supports a wide range of layer2/3, inter-VLAN routing, MPLS, QoS and many other high-end functionality, natural fit for core layer networking. The switch stacking technology allows you to control the single stack to expand network capacity.

S5900-24S 24 port 10GbE fiber switch ideal for core switch

Figure 1: FS S5900-24S 24 port 10GbE fiber switch is a routing Ethernet core switch with high-performance, high-security, and switch stacking technology, expanding your network to 418Gbps.

What Is Normal Switch?

What we mentioned normal switch is often an edge switch/access switch in the access layer of enterprise network. Or in cases where network topology is not involved such as small office and home environment, normal switches may be used solely to connect end devices. Such access switch in the market often comes with copper switch with a few SFP/SFP+ port. Say S2800-24T4F fanless gigabit managed 24 port switch with 4 combo SFP slots. This quiet energy-saving access switch with abundant ports is ideal for SMBs, labs, schools and other places requiring silent operation. To provide PoE for your PDs, gigabit PoE switch is also widely used as access switch for IP surveillance cameras, VoIP phones and WAPs.

S2800-24T4F fanless 24 port gigabit switch as edge switch rather than core switch

Figure 2: FS recommends S2800-24T4F 24 port gigabit switch for your access layer to ensure quiet and reliable operation.

Core Switch vs Edge Switch: What Is the Difference?

  • Network Layer Location

Core switch is a powerful backbone switch in the central of the network core layer, which centralizes multiple aggregation switches to the core and implements LAN routing. Normal edge switch is in access layer to directly connect multiple end devices.

  • Hardware and Software Feature

What makes a best core switch? A core witch often comes with optimized hardware and software design. A remarkable feature is owning redundancy in configurations such as ports, power and PSU. A core backbone switch is also a layer 3 switch with internal firewall capability as part of its routing functionality. A normal edge switch usually doesn’t require such high demands. Actually it may even not a managed switch in simple end user connection.

core switch vs edge switch deployment scenario

Figure 3: Deploying FS 10G fiber switch as core switch, gigabit PoE switches for PDs and gigabit 48 port switches as access switches.

Conclusion

Core switch is a fatal component in enterprise network core layer, which functions both switching and routing. Compared core switch vs edge switch, core layer switch owns advanced features in hardware and software to cater for high-end applications. Though core switch price is higher than a normal switch, deploying best core switches in the core layer is a must to ensure a reliable backbone. FS provides cost-effective core switch and enterprise network solutions for different applications. Any other information to know, you can visit our official website and blog.

Mikrotik Switches Vs Cisco Switches

As a worldwide leader in IT and fiber optical networking, Cisco switches play a leading role in manufacturing network switches and in providing switching solutions for data center and enterprise networks with large and medium-size forms. MikroTik, a Latvian company which was founded in 1996 to develop routers and wireless ISP systems. Their cloud switches are highly favored by many Ethernet users in recent years. And thus, people are entangled with Cisco and Mikrotik switches. This article would give brief introduction to Cisco and Mikrotik switches, and put emphasis on Mikrotik Switches Vs Cisco Switches.

Cisco Switches

According to different usage, Cisco divided their switches into the following categories: LAN Access Switches, LAN Digital Building Switches, LAN Core and Distribution Switches, Data Center Switches, Service Provider Switches, Industrial Ethernet Switches, Virtual Networking and Small Business Switches. And every category has its switching series. The Cisco Catalyst series switch delivers ease of management and configuration for small to medium-sized enterprise wiring closets in a single system, without the need for additional modules. The following list is about the Cisco Catalyst series switch.

Cisco Catalyst series switch

Mikrotik Switches

Comparing to Cisco switches, the total amount of Mikrotik switches is much smaller. According to the official website of Mikrotik, there are only twelve Mikrotik switches. Ethernet smart switches and cloud core router switches are two series switches of Mikrotik switches. The cloud core switch, or cloud router switch, abbreviated as CRS, is a highly configurable switch, powered by RouterOS. They are the new products of Mokrotik switches. For the cloud router switch, there are nine models currently available. Here lists three different cases of the cloud core switch:

  • CRS125-24G-1S-2HnD-IN (integrated wireless, indoor case)
  • CRS125-24G-1S-IN (indoor case)
  • CRS125-24G-1S-RM (rackmount case)

Mikrotik Switches Vs Cisco Switches

—CPU

The CPU on both Cisco and Mikrotik switches is used for management purposes (snmp stats, cli management, etc) and it does not affect the data path. Switching is not done in CPU, neither on Cisco nor on Mikrotik. Switching is done on dedicated ASIC chips specifically designed for this job (thus giving wirespeed). So comparing the CPUs won’t mean much about forwarding performance – which is the metric you should care about.

—Power Consumption

One of big problems with Mikrotik switches is their power. The buyers would prefer to pay another couple hundred dollars to have dual power supplies that are removable. And thus, many Ethernet users cannot use Mikrotik in these cases. Comparing to Mikrotik switches, Cisco switches have less power consumption by their advanced technology.

—Network Monitoring Software Systems

Most network monitoring software systems natively understand, support and auto-detect Cisco devices and support Cisco SNMP OIDs (CPU, temp, load, bandwidth, errors, power supply status, and many other sub-system counters in a Cisco device.

When configuring your existing network monitor system(s), your network monitor system(s) may not even know what a Mikrotik is and probably does not have native built-in MIBs/OIDs used by SNMP to auto-check/monitor a network. Thus, an administrator would probably need to configure the Mikrotik graphic icons and configure all of the SNMP checks for MIBs/OIDs from/to a Mikrotik.

Mikrotik Switches Vs Cisco Switches: How to Select?

Mikrotik routers and switches are great. Most people like them and use them almost everywhere. However, because Mikrotik is still the new kid on the block when it comes to carrier-grade commercial-grade business grade high-throughput products, it may sometimes be a little difficult to find local network technicians or local phone support for Mikrotik products when adding new equipment into your network. So Cisco switch is more solid and people are more satisfied with them.

A Comprehensive Understanding of CFP Modules

As a new emerging technology, 100G is some sort of evolution and part of revolution. The new CFP (C form-factor pluggable) optics is now a revolutionary step as one form factor of 100G optic transceiver. The CFP modules offer the enabling step for cost-effective and successful 100G deployment. So what is it? And how does it work in 100G network? This article would give a comprehensive introduction to CFP module.

100G CFP module

CFP Wiki

Abbreviated as CFP module, C Form-Factor Pluggable transceiver is a multi-sourced pluggable transceiver used in the transmission of high-speed digital signals. It is specified by a multi-source agreement (MSA) between competing manufacturers. The c stands for the Latin letter C used to express the number 100 (centum), since the standard was primarily developed for 100 Gigabit Ethernet systems. It is a hot-swappable input/output transceiver that is used in the data communication and telecommunication networks.

The CFP module was designed after the small form-factor pluggable transceiver (SFP) interface, but is significantly larger to support 100 Gbit/s. While the electrical connection of a CFP module uses 10 x 10 Gbit/s lanes in each direction (RX, TX) the optical connection can support both 10 x 10 Gbit/s and 4 x 25 Gbit/s variants of 100 Gbit/s interconnects (typically referred to as 100GBASE-SR10 in 100 meter MMF, 100G CFP LR10 and 100G CFP LR4 in 10 km SMF reach, and 100GBASE-ER10 and 100GBASE-ER4 in 40 km SMF reach respectively.)

Core Features of CFP Modules

– Support to 103 Gbps and 112 Gbps aggregate bit rates.

– Connector Interface

– Operating Case Temperature

– Diagnostic Monitoring

– RoHS6 Compliant

– Single 3.3V Supply for Power and a Power dissipation < 12W

One distinctive feature of CFP modules is that they support digital diagnostic monitoring functions or the digital optical monitoring. This is the feature that gives users the ability to monitor the real-time parameters such as the optical output power, the optical input power, the temperature, the laser bias current and the transceiver supply voltage.

Inner Structure of CFP Modules

The basic CFP modules consist of the following parts.

1. An Integrated Coherent Optics Transmitter which sends the TX optical signal.

2. An Integrated Coherent Optics Receiver which receives the RX optical signals.

3. The CFP connector

4. Coherent DSP

Most of the CFP module adhere OIF CFP-ACO (Analog Coherent Signals) and are connectable to multiple DSP’s. The biggest engineering challenge that CFP2 faces is the adoption of the high-speed 25 Gbps electrical interface due to the reason that the CFP was based on the third generation.

It can be a multimode parallel optic transceiver module that is designed to offer high-density 100G Ethernet and Optical Transport Network (OTN). The device is designed to offer maximization of the delivery of the 10G data channels for the 100G networks that support 100 Gbps SR10 and 10 X 10 Gbps.

Development of CFP Modules

The original CFP specification was proposed at a time when 10 Gbit/s signals were far more achievable than 25 Gbit/s signals. As such to achieve 100 Gbit/s line rate, the most affordable solution was based on 10 lanes of 10 Gbit/s. However, as expected, improvements in technology has allowed higher performance and higher density. Hence the development of the CFP2 and CFP4 specifications. While electrical similar, they specify a form-factor of 1/2 and 1/4 respectively in size of the original specification. Note that CFP, CFP2 and CFP4 optical transceiver are not interchangeable (but would be inter-operable at the optical interface with appropriate connectors). The following table shows the basic parameter of CFP, CFP2 and CFP4 transceivers.

basic parameter of CFP, CFP2 and CFP4 transceivers

Conclusion

In this article, we mainly introduced the definition, core features, inner structure and development of CFP modules. Comparing to 100G QSFP28 transceiver, CFP price is not so competitive. But CFP optical transceiver is still the key to cost-effective and reliable 100G deployment, and it has been widely deployed in OTU4 411-9D1F, 100GBASE-LR4 Ethernet and data centers.

Related article:
100G QSFP28 and CFP Transceiver Cabling Solutions

Stacking Vs. Chassis Switch: How to Choose?

Maximizing scalability and optimizing performance are two paramount factors when you design or upgrade your network. It is hard to find the right balance. Given that you need more than 48 ports in a wiring closet, but you could not decide which type of switches to buy. Stacking switch or non-stacking switch? Or does a modular chassis switch solution make more sense? In this article, we would make a comparison between stacking and chassis access switches and guide you to make an appropriate decision.

Stacking Switches Solutions

Over the years, stacking network switches have been highly favored by lots of Ethernet users and been a core component of an enterprise-grade switch. So what is reason for the popularity of stacking switches? By using stacking switches, we can add ports as we need them by simply purchasing another switch and adding it to the stack. We can stack up to nine Cisco 3750-X switches and have 432 x 10/100/1000 ports and 18 x 10 Gbps ports. We can do this using only 9RU’s of rack space. A chassis would require over double the rack space to achieve this access port density. This makes these switches very popular as top-of-rack switches in the data center.

brocad-stackable-switches

Figure1: Brocade Stackable Switches (Resource: www.Brocade.com)

Pros of Stacking Switches
  • Pay-as-you-grow
  • Small Physical Footprint
  • Convenient 100v Power Standard
  • Virtual Chassis Capability
  • Cross-Stack EtherChannel
Cons of Stacking Switches
  • Management Difficulties
  • Power Demands
  • Software Complexity
  • Instability
Chassis Switches Solutions

Chassis devices, often being “premier” devices, may offer software and/or hardware features unavailable on a stack. They are the flagship models of every vendor’s switching line. In contrast to the fixed configuration switches, it is engineered to operate as single integrated system. Configuring high availability is simple and it works every single time. A failed line card will not bring down the entire chassis. Additionally, a chassis will drive consistency in deployment.

Cisco Chassis Switch

Figure2: Cisco Chassis Switches (Resource: www.Cisco.com)

Pros of Stacking Switches
  • Solid High Availability Features
  • Modular Design
  • Supports Wide Range of Line Cards
  • Simple to Deploy
Cons of Stacking Switches
  • Physical Space (twice the space of stacks)
  • Expensive Power Supplies
  • 220v Power for PoE Solutions
How to Choose?

Just as the same as the every comparison on the similar kits, the decision really depends on your actual requirements. Once we have this, finding the right hardware is very straightforward. It is important to balance the cost of acquisition versus the cost of operations and impact to the business due to outages. And that is what we always thinking about when we make a decision.

In this article, we mainly provide the detailed information about stacking and chassis switches solutions, and offer you relatively enough information to help you to make a decision on choosing the best switching solutions for setting up or upgrading your network. There are too many variables to give a one-size-fits-all recommendation, but in general chassis Ethernet switches’ solutions are our preference. In addition, you should keep in mind that pricing should not be the focused too much. We can get both designs for a pretty reasonable price, regardless of requirements. If your network can benefit from both stackables and chassis, the chassis solution would be a good choice.

Related Article: Stacked switches vs Chassis switch at the core

Why Use Media Converters in LAN & MAN?

media-converterNowadays, people are widely using media converters for LAN (Local Area Networks) and MAN (Metro Area Network). As for the LAN, media converter plays an important role in combining the fiber optic cabling and active equipment with the current copper structured cabling. And in the case of MAN, media converter is also significant in conversing electrical signals into optical signals which increases the service deployment and decreases the service cost for customers. This post is going to further explain the advantages of using media converters in LAN and MAN respectively.

Advantages of Using Media Converter in LAN

At first, media converters are simple devices just used to connect two dissimilar media types such as twisted pair with fiber optic cabling. Today, category of media converters increases a lot. And the function of media converter is not single and can meet more requirements. Media converters including fiber to RJ45 converters, SFP Ethernet converters, OEO converters, mode converters, fiber video converters, etc. can be found in the market.

Copper and Fiber Conversion

Now some LAN is still structured with twisted pair wiring. As a result, the transmission distance is greatly limited with only 100 meters. To extend the data transmission distance, fiber cable gains the popularity since it can support longer transmission distance and it’s more and more inexpensive. But in practice, copper is familiar and easier to be installed. Besides, many network devices still have copper ports. It would cost too much to replace all the expensive equipment with fiber optics. So media converter is applied to realize the copper & fiber conversion with the cheapest price. Media converters make it possible to migrate a local network to fiber while maintaining the existing infrastructure.

10-100base-t-to-100base-fx-xrj45-media-converter

Figure 1. 10/100Base-T to 100base-FX Single Fiber Media Converter

Speeds Conversion

When connecting legacy 10BASE-T network segments to a newer 100BASE-FX Fast Ethernet infrastructure, media converter is the best solution. With one RJ45 port and one SFP socket, this 10/100Base-T to 100base-X SFP Ethernet fiber media converter can mediate between 10/100M UTP ports and 100M optical fiber ports. And it can reduce electromagnetic interference and extend the distance up to 100 km. Media converters can support network speeds from 10 Mbps to 10 Gbps.

speed-conversion

Figure 2.  Media Converter Connecting Different Speed
Bridging Two LANs over Fiber

Media converters are also used to expand the reach of the LAN to cover more locations. A converter can connect multiple LANs to form one large “campus area network” that spans over a limited geographic area. As premises networks are primarily copper-based, media converters can connect two distance switches with single-mode fiber and extend the reach of the LAN up to 130 km.

Saving Cost for FTTD

Existing data rate in the LAN backbone at 100Mbps or Gigabit speeds, fiber can accommodate high-bandwidth applications such as streaming media and voice over IP for more secure desktop connections. Media converters can make FTTD (fiber to the desktop) cost-effective in the LAN. With media converters, the cost of expensive fiber home which requires all-fiber switches, patch panels and network interface cards can be saved by converting in the telecommunications room and at the desktop.fttd

Figure 3.  Media Converters Make FTTD a Reality.

Advantages of Using Media Converter in MAN

Ethernet is the dominate LAN protocol with the highest market penetration. Past 10/100Mbps connections in LAN can’t meet the demands for high-speed data traffic. With the publication of the 10, 40 and 100 Gigabit Ethernet standard, the applications space for Ethernet expands from the LAN to MAN.

Maintaining Optical Circuits

Media converters are deployed in the MAN to provide the physical layer connection and to bridge the bandwidth gap that exists between LAN and MAN. In the LAN, the structured cabling is often twisted-pair copper cable or multi-mode fiber. While the cabling is often single-mode fiber in the MAN. So media converters are used at both ends of the first mile to provide the electrical-to-optical conversion from the POP (point of presence) switching router to single-mode fiber, and back to 10/100/1000BASE-T Ethernet at the customer premises. At the same time, if the customer needs to increase the internet speed, the bit rate can be increased through the POP switch and the converter will automatically adapt to the increased speed, avoiding a visit to the customer site or POP.

Increasing Flexibility

Media converters can realize the connections between copper switch ports and optical access to get more flexible and further. Media converters can support multiple types of media from copper to multimode and single-mode fiber. Single-mode converters cover distances up to 80 km with 1310nm optics and even 130 km with 1550 nm optics.

Media converters can also enhance the consistency of service. On one side, if there is any problem, the network administrator can troubleshoot one circuit and keep other customers’ connections running. On the contrary, if a fixed port switch goes down, all connections will be down simultaneously when repairing a faulty port. On the other side, customers can used the media converter as an optical demarcation point, which brings cost savings and simplicity.

Conclusion

There are many benefits of using media converter in LAN and MAN, such as copper and fiber conversion, speed conversion, cost reduction, simple network troubleshooting and so on. Media converter is not only the optical demarcation between LAN and MAN, but also the bridge between LAN and optical backbone of service provider. With such a cost-effective solution, what’s the reason not to use?