Switch selection criteria in Network Monitoring

Switch selection criteria in Network Monitoring

With the increasing use of high-definition cameras, how to choose a suitable switch to monitor the overall network architecture performance has become a very important role in the early design of the high-definition monitoring system and project quotation. A proper switch can not only exert the functions of the monitoring network, but also effectively reduce the waste of resources.

The monitoring network has three layers of architecture: core layer, aggregation layer, and access layer.

Take a p camera as an example and select the corresponding switch. The front-end 20-way P is connected to one access layer switch.

Selection of access layer switches:

Condition 1: Camera Ma stream: 4.5 Mbps. 20 cameras are 20*4.5 = 90 Mbps. That is to say, the access layer switch upload port must meet the transmission rate requirement of 90 Mbps/S, considering the actual transmission rate of A vswitch (usually 30% of the nominal value and about 30 M of M), the access layer switch should use a M upload port.

Condition 2: The backboard bandwidth of the vswitch. For example, if you select a 24-port switch, the vswitch comes with two M ports, with a total of 26 ports, the bandwidth requirement of the access layer switch is: (24*100 M * 2 + 1000*2*2)/1000 = 8 Gbps.

Condition 3: Packet forwarding rate: If the packet forwarding rate of A 1.488 M port is 100 Mpps/s, the switch switching rate at the access layer is: (24*1000 M/M + 2) * 1.488 = 6.55 Mpps/S.

Generally, we call a line rate switch that meets conditions 2 and 3. For example, H3C S1026T can meet the line rate switching capability and has 24 m ports and 2 m electrical ports.

According to the above conditions, when a 20-channel P camera is connected to a switch, the switch must have 1 m upload port and more than 20 m access ports.

Selection of aggregation layer switches:

For a total of five H3C S1026T switches, the traffic at the aggregation layer is 90*5 = 450 Mbit/S. Therefore, the upload port at the aggregation layer must be over Mbit/S.

If five IPCAM switches are connected to one, we usually use an eight-port switch. Does this eight-port switch meet the requirements? Then, we should calculate at least three capabilities of this vswitch.

1. Board bandwidth: number of ports * port speed * 2 = Board bandwidth, 8*100*2 = 1.6 Gbps/S.

2. packet Switching rate: number of ports * port speed/1000*1.488 Mpps = packet switching rate, 8*100/1000*1.488 = 1.20 Mpps/S, the packet exchange rate of some switches sometimes cannot meet this requirement, so it is a non-wire speed switch. When a large volume of throughput is carried out, it is easy to cause latency.

3. cascade port bandwidth: the number of bit streams * of IPCAM = the minimum bandwidth of the upload port, 4.5*5 = 22.5 Mbps/S. Generally, when the bandwidth of IPCAM exceeds 45 Mbps, we recommend that you use a m cascade port.

A vswitch that meets the preceding requirements is a suitable vswitch.