Three layer architecture : Core, Distribution and Access Layers
Three layer architecture is the architecture where you are designing the core, distribution and access layer in your LAN network.
Whenever we have the opportunity to design the LAN network, where we need to design the 3 layer architecture, we always think about the core, distribution and access layers. What should be there at the core and distribution layer which can handle my aggregated LAN traffic and then routed to the WAN router.
It totally depends upon the users on the sites and the applications used by the user. If i am talking the rough estimate or rough example in which we can take like we have 100 users on site and they are using some applications like oracle, share point and Mails. So every application is taken as some KB bandwidth so lets suppose it's 20 Kbps, so every user have the bandwidth consumption of 60 Kbps or take it 100 Kbps/user. Now we have 100 users on the site. So estimate is the site require the full of 10 Mbps WAN bandwidth but for the best practice we can take 15 Mbps aggregated Ethernet circuits here.
Now question what will be the design on my WAN and LAN side ? Any clue, Any thoughts ?
Well starting from the WAN to LAN, we can design like on the WAN side we can proposed Cisco 1941 router as Customer's Edge router which will be connected to the MPLS side of Provider's Edge router with routing protocol( whatever you want to use ).
On the LAN side, i suggest Cisco 3850 boxes on Core and distribution and Cisco 2960 for the access to connect the users. This is just an example to explain the best practices in the design.
We have various LAN core and distribution switches which can be used accordingly as per the design and enterprise network requirements.
Let me talk about the Cisco Portfolio switch which can be used in core and distribution layers of enterprise network as per the design requirements.These devices are :
Whenever we have the opportunity to design the LAN network, where we need to design the 3 layer architecture, we always think about the core, distribution and access layers. What should be there at the core and distribution layer which can handle my aggregated LAN traffic and then routed to the WAN router.
It totally depends upon the users on the sites and the applications used by the user. If i am talking the rough estimate or rough example in which we can take like we have 100 users on site and they are using some applications like oracle, share point and Mails. So every application is taken as some KB bandwidth so lets suppose it's 20 Kbps, so every user have the bandwidth consumption of 60 Kbps or take it 100 Kbps/user. Now we have 100 users on the site. So estimate is the site require the full of 10 Mbps WAN bandwidth but for the best practice we can take 15 Mbps aggregated Ethernet circuits here.
Now question what will be the design on my WAN and LAN side ? Any clue, Any thoughts ?
Well starting from the WAN to LAN, we can design like on the WAN side we can proposed Cisco 1941 router as Customer's Edge router which will be connected to the MPLS side of Provider's Edge router with routing protocol( whatever you want to use ).
On the LAN side, i suggest Cisco 3850 boxes on Core and distribution and Cisco 2960 for the access to connect the users. This is just an example to explain the best practices in the design.
We have various LAN core and distribution switches which can be used accordingly as per the design and enterprise network requirements.
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| Fig 1-1 Three layer architecture |
Let me talk about the Cisco Portfolio switch which can be used in core and distribution layers of enterprise network as per the design requirements.These devices are :
- Cisco Nexus 7000 Series
- Cisco catalyst 6800 Switch
- Cisco catalyst 6500 Switch
- Cisco catalyst 4500-X switches
- Cisco 3850 Switches
- Meraki MS400 series Switches
Cisco Access switches used widely in the networks are :
- Cisco 4500 E Switch
- Cisco 3850 Switch
- Cisco 3600 Switch
- Cisco 2960 X/XR/L Switches
- Meraki MS series switches
If i am talking about the Juniper Switches in core,distribution layers and even in the access layers of network, they can be :
- Juniper EX2200
- Juniper EX2300
- Juniper EX3300
- Juniper EX3400
- Juniper EX4200
- Juniper EX4550
- Juniper EX4600
- Juniper EX9200
On the other hand, Huawei has lot of switches in their portfolio for Core, distribution and Access layers network recommendations. These switches are
- Huawei S12700 Series
- Huawei S9700 Series
- Huawei S7700 Series
- Huawei S6720 Series
- Huawei S6700 Series
- Huawei S5720-SI/EI/LI/HI Series
- Huawei S5700-SI/EI/LI/HI Series
- Huawei S3700 Series
- Huawei S2700 Series
- Huawei S1700 Series
So i just touch upon the fact that these all three big giants have lot of switches in their portfolio for the different requirements and demands in the network. It's you who will gonna decide which switch is fit in your network and how you are going to design the network with standard and clean requirements. We have various scenarios in this LAN design and that can be like we are designing the campus core network, small offices or datacenter. The basic requirement is the traffic flows from end users to the WAN via LAN core, distribution and access layers.
It also take into account that access layer switches are generally L2 switches but at the core and distribution it is recommended that you can use L3 switches instead of L2 switches.
Designing the LAN network is one of the most interesting parts where people actually confused about the requirement and the infrastructure based on the users. It is recommended to design the network on the basis of the user count in your network
