GPRS/TCP/IP traffic Calculation

GPRS/CDMA traffic statistics method

Traffic Statistics mainly include the following three parts:

1. log on to the network and establish a TCP Link
The PPP handshake phase is about 12 ~ 16 PPP handshake packets, each of which is 30 bytes. 30*16 = 480 bytes.
TCP connection phase: 40 × 3 = 120 bytes
Registration: 61 + 40 = 100 bytes
A total of 700 bytes is required. The calculated traffic is 700*8 = 5600bit.

Note: even if the center is not enabled, DTU must still try to establish a TCP connection, which will generate traffic.

2. Establish a TCP link and transmit data
PPP encapsulation + IP Encapsulation + TCP encapsulation + Data

For example, if the send heartbeat of DTU is only Fe, the traffic generated is as follows:
TCP + IP header 40 bytes, Data Part 1 byte, PPP header 7E 21, PPP tail checksum 2-bit + 1 7E, the total size is 40 + 1 + 5 = 46 bytes, and the statistical traffic is 46 × 8 = percentile bit.

The heartbeat response generates the same traffic as above.

Iii. Junk data
However, apart from normal data transmission, some data is often sent from other hosts on the network. For example, the destination port is a UDP packet such as 445, which is not sent by DTU or the data center, some junk data is out of the control of DTU terminals or data centers.