Got it

How to select the appropriate switch?

Latest reply: Mar 29, 2021 11:02:08 343 42 16 0 3

Hi there!


Choosing the most appropriate switch can be a cumbersome and difficult task, especially if you've got a wide range of operations and user wishlists to cover. Today I’ll try to simplify the process for you so you can choose the switch that matches your tailored requirement.


STEP 1


Chose the power type you have in your datacenter / IT room. See if you have AC power or DC power. Based on that, choose the power cable required.


Secondly, see if you require a redundant power or single power supply. As a suggestion, always go for the redundant power supply whenever there is a possibility. This is to make sure that if there is a power outage on one line or there is a power supply failure, the switch can still work with the redundancy provided.


If selected switch doesn’t support secondary power supply, try to add an “ATS” device. This device basically has 2 inputs and a single output. You can use the output to give power to the switch and use the inputs to get the power from 2 different sources or locations.


STEP 2


Calculate what kind of downlink ports are required. Huawei offers multiple variants, as shown below:


  • FE Electrical;


  • GE Electrical;


  • GE Optical;


  • 10GE Electrical;


  • 10GE Optical;


  • Multi-GE Electrical;


  • 25GE Optical.


STEP 3


Calculate what kind of uplink ports are required. Huawei offers multiple variants, as shown below:


  • FE Electrical;


  • GE Electrical;


  • GE Optical;


  • GE Combo;


  • 10GE Optical;


  • 40GE Optical;


  • 100GE Optical;


  • 25GE Optical.


STEP 4


Check with the requirement team how many ports are required on a switch. Huawei has following ranges available on access switches:


  • 5-10;


  • 12-18;


  • 20-36;


  • 44-52;


  • >52.

 

STEP 5


Now that the hardware has been decided, check what kind of features are required on the switch. Thef following high-level features are offered (a lot more features are available, but these are the major ones that help in the categorization of the switches):


  • PoE;


  • IPv6;


  • VxLAN;


  • iStack.


STEP 6


You can also choose which series they should be from, like from LI series, SI series, EI Series or HI Series. LI Series is about basic L2 switches, SI are basic L3 switches, EI switches provide complete L3 features and HI offers advanced L3 features on a switch.

 

By performing all these steps, you can select the switch meeting all your requirements. To make things simpler, Huawei also offers the same in the Unistar app. You can access it here. This tool looks like this:


switch

Source: Huawei SCT Page

 

STEP 7


After completing the above steps, you might end up with more than one options to chose a switch from. Now, to further narrow our search down and chose the most appropriate switch, we have to go through one final detailing step.


We’ll calculate the switch throughput and forwarding capacity to get the best results. We can calculate the throughput by using the following method:


1. calculate the type of ports required - that is, see if you need 100M/1G/10G ports;alculate the number of ports required.


2. note that you might end up with a mixture of ports (some will be 1G, others 10G and even 40G) and that’s okay;


3. now we’ll calculate the throughput requirement:


Switch throughput = Number of ports * type of ports*2


You might ask, why multiply it by 2 - it is because the port throughput is normally marketed at half-duplex and the switch is configured at full-duplex, thus doubling the throughput of the port.


For example, you need a 24-port switch with 24 x 1G downlink ports and 4 x 10G uplink ports, so we’ll calculate the throughput requirement in this way:


Switch Throughput = (24 x 1 + 4 x 10) *2

                                      = (24 40)*2

                                      = 64 * 2

Switch Throughput = 128 Gbps

 

The next step will be to calculate the forwarding capacity of the switch. The forwarding capacity means how many packets per second a switch can forward. The Ethernet packet sizes are limited because Ethernet conflict detection mechanisms are enabled and as per the standard, the minimum data frame has to be 84 bytes. It is calculated using the following:


Minimum data packet size: 64 bytes

Inter-frame gap: 12 bytes

Preamble bytes: 8 bytes

Total: 64 + 12 + 8 = 84 bytes


Take the 1 Gbit/s Ethernet interface as an example. Every 8 bits form a byte. Therefore, the Ethernet interface rate of 1000 Mbit/s =125 Mbyte/s, that is, the Ethernet interface can forward 125M bytes =12,500,000,000 byte per second. Assuming that all data frames transmitted in the worst case scenario are the smallest 84 byte, the data frame forwarded by the 1000 Mbit/s Ethernet port per second is 12500000000/84=148,809,524pps (frame/second) =148.8Mpps=1.488Mpps.

 

Therefore, it can be concluded that the packet forwarding rate of the 1000 Mbit/s Ethernet interface is 1.488Mpps, then the packet forwarding rate of the 10G Ethernet interface is 14.88Mpps.

 

For example, if there is a 48-port 10/100/1000 Base-TX Ethernet switch, the packet forwarding rate of the switch is 48*1.488Mpps=69.5Mpps, plus four 10GE ports 4*14.88Mpps=59.52Mpps. So, the total is 69.5Mpps+59.52Mpps=129.02Mpps. That is, a 48-port 1000 Mbit/s + 4x10G Ethernet switch can implement line-rate forwarding only when the packet forwarding rate of the entire device reaches 129.02Mpps.

 

STEP 8


Now, that you have selected the switch, there might be some extra customer requirements like WLAN licenses or MACSec requirements on the switch. For these, you should select the “H” series switches; that provides the highest level of features available in the L3 switch.


CONCLUSION


Selecting an appropriate switch is as critical as the network function itself, because choosing a high-end switch will drive the cost up, while choosing a low-end switch means compromising on the services. So, using these steps, you can choose the switch with 100% accuracy.

 

Hope this helps. In case of any questions, please do let me know in the comments!

The post is synchronized to: Community Blog

  • x
  • convention:

ChandC
Created Feb 21, 2021 10:14:07

Important topic. Thanks for sharing.
View more
  • x
  • convention:

umaryaqub
umaryaqub Created Feb 22, 2021 05:26:51 (0) (0)
Thanks for your support  
IndianKid
Moderator Author Created Feb 21, 2021 10:25:50

useful stuff
View more
  • x
  • convention:

umaryaqub
umaryaqub Created Feb 22, 2021 05:26:59 (0) (0)
Thanks  
I%26%23039%3Bm%20not%20insane%2C%20my%20mother%20had%20me%20tested!
wissal
MVE Author Created Feb 21, 2021 11:43:18

Very useful guideline.
View more
  • x
  • convention:

umaryaqub
umaryaqub Created Feb 22, 2021 05:27:11 (0) (0)
Indeed. Thanks for your support  
I%20would%20like%20to%20share%20with%20you%20my%20experience%2C%20I%20am%20a%20telecommunications%20engineer%2C%20currently%20senior%20project%20manager%20at%20a%20telecom%20operator%20who%20is%20a%20partner%20of%20Huawei%2C%20in%20the%20radio%20access%20networks%20department%2C%20during%20my%20career%20I%20have%20managed%20various%20projects%20for%20various%20network%20nodes.%3Cbr%2F%3EAt%20the%20same%20time%2C%20temporarily%20I%20give%20courses%20in%20telecom%20engineering%20schools%2C%20to%20bring%20the%20operational%20side.
SidzHuawei
Created Feb 21, 2021 16:35:53

Awesome guidelines, I don't have access to unistar but I'll apply again
View more
  • x
  • convention:

umaryaqub
umaryaqub Created Feb 22, 2021 05:27:29 (0) (0)
Please apply through your partner account and you'll get it.  
Saqib123
Created Feb 21, 2021 16:36:44

Thanks for sharing ;)
View more
  • x
  • convention:

umaryaqub
umaryaqub Created Feb 22, 2021 05:27:41 (0) (0)
Thanks for your support  
zaheernew
zaheernew Reply umaryaqub  Created Feb 23, 2021 07:53:36 (0) (0)
cool  
zaheernew
Created Feb 22, 2021 04:31:14

useful
View more
  • x
  • convention:

umaryaqub
umaryaqub Created Feb 22, 2021 05:27:49 (0) (0)
Thanks  
zaheernew
zaheernew Reply umaryaqub  Created Feb 22, 2021 10:32:24 (0) (0)
 
I'm%20Tech%20professional
alopez
MVE Created Feb 22, 2021 06:50:07

Sensational and very useful post, dear friend!!
Thank you!!How to select the appropriate switch?-3804429-1
View more
  • x
  • convention:

umaryaqub
umaryaqub Created Feb 24, 2021 07:19:59 (0) (0)
Thanks  
DragonVN
Created Feb 28, 2021 07:25:50

Useful. Thanks for sharing
View more
  • x
  • convention:

umaryaqub
umaryaqub Created Feb 28, 2021 12:49:40 (0) (0)
Thanks  
VikkiBoy
Created Mar 5, 2021 11:02:23

Very useful
View more
  • x
  • convention:

user_3015189
user_3015189 Created Mar 8, 2021 21:15:34 (0) (0)
You're right  
umaryaqub
umaryaqub Created Mar 29, 2021 08:09:25 (0) (0)
Thanks  
123
Back to list

Comment

You need to log in to comment to the post Login | Register
Comment

Notice: To protect the legitimate rights and interests of you, the community, and third parties, do not release content that may bring legal risks to all parties, including but are not limited to the following:
  • Politically sensitive content
  • Content concerning pornography, gambling, and drug abuse
  • Content that may disclose or infringe upon others ' commercial secrets, intellectual properties, including trade marks, copyrights, and patents, and personal privacy
Do not share your account and password with others. All operations performed using your account will be regarded as your own actions and all consequences arising therefrom will be borne by you. For details, see " Privacy."

My Followers

Login and enjoy all the member benefits

Login

Block
Are you sure to block this user?
Users on your blacklist cannot comment on your post,cannot mention you, cannot send you private messages.
Reminder
Please bind your phone number to obtain invitation bonus.