Hi,
For switches, backplane speed is with respect to the Virtual chassis where the switches are connected to eachother using VCP ports. Hence, backplane speed is the capapcity of the VCP ports. /
//For eg: and EX4550 can have a maximum of 4 VCP ports with each VCP port having a capacity of 64Gbps full-duplex. Hence, the maximum backplane speed for the VC is 256 Gbps full duplex.//
//Lets try to understand the data rate and system throughput.
Data rate: Data rate is w.r.t the network ports and can simply be defined as the maximum possible traffic that can be sent through all these ports.
Ex: EX4550 can have a maximum of 48 10Gbps ports. That makes 480 Gbps simplex traffic and 960 Gbps full duplex non-blocking traffic and this is the maximum.//
//When it comes to the system throughput, to define it, it is the practical value the link can acheive in real time considering the latency, additional headers in case of fragmentation and many other factors. For eg, this can be calculated as the maximum packets per second a device can handle in real time.
For ex: EX4550 provides 14.88 Mpps of throughput per port at the minimum Ethernet frame size. With a maximum of 48 ports, the Maximum throughput it can acheive is 14.88 * 48 = 714 Mpps.
You can refer and compare these specifications for the EX4550 at https://www.juniper.net/us/en/products-services/switching/ex-series/ex4550/specs/
Thanks,
Pradeep
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