PCM device Ethernet bandwidth allocation problem

In fact the Ethernet bandwidth of a PCM device mainly depends on two factors: 1. How many 2M circuits can you provide? 2. What services are transmitted in addition to Ethernet.

First of all, it should be noted that the standard 2M circuit consists of 32 time slots, which 1~15 time slots and 17~31 time slots. A total of 30 time slots can be used to carry 64k narrowband services, which can be allocated to Ethernet. The following is a brief description of the calculation method of Ethernet bandwidth of PCM devices.

We can take an extreme example to illustrate, if you can only provide one 2M circuit as a transmission channel and transmit 30channel telephone (each phone occupies 1 time slot), then there is no extra time slot for Ethernet use. If the same condition (providing one link 2M), only 10 channel telephone are transmitted, then there are 20 time slots left for Ethernet use, and the Ethernet bandwidth is equal to (30-10)*64k, which is 1280k.

There are some PCM devices on the market that allow two or more 2M circuits to be connected. If you want to transfer 30 channels telephone and 1 channel Ethernet, you need to provide at least two 2M circuits, one for 30channel telephone (occupying 30). The time slot, which just occupies 1 channel 2M circuit). Another channel is used to transmit Ethernet, and the Ethernet bandwidth is 30*64k, which is 1920k, it is about 2M. If you can provide two 2M circuits, but only need to transmit 10channel telephone and 1 channel Ethernet, then this Ethernet can allocate bandwidth across 2M (provided that PCM device support is required), 10 calls only occupy 10 Gap, there are still 20+30 time slots that can be allocated for Ethernet use, it is 3200k, but some PCM devices on the market do not support the allocation of Ethernet bandwidth across 2M, so you need to know clearly before purchasing.