METHOD AND APPARATUS FOR SELECTING PASSIVE PORT OF TRANSPARENT CLOCK NODE BASED ON PTP

摘要

Provided are a transparent clock passive port election method and device based on the PTP protocol. In the method, by extracting the TLV field of a received announce message, a first port of a network device acquires the clock identification information, forwarding times information and port identification information carried in the TLV field, and then compares the forwarding times information and clock identification information carried in the TLV field to the forwarding times information carried in the TLV field contained in a received announce message from a port by itself, and its own clock identification information, so as to select a port as a passive port. Therefore, by adding the comparison factors, such as clock identification information, forwarding times information and port identification information, in the TLV field of an announce message, a transparent clock is allowed to support the PTP protocol, thus avoiding a protocol storm formed by a PTP message in a complex topology network and a ring network constituted by the transparent clock to improve the stability of the network.

主权项

1. A method for selecting a passive port of a transparent clock node based on PTP, comprising:
a port of a network device receiving an Announce packet transmitted from another network device, extracting a TLV field of the Announce packet, and obtaining clock identifier information, number-of-forwarding information and port identifier information carried in the TLV field, wherein the network device are provided with at least two ports; judging whether the port of the network device is a slave port; if it is judged that the port of the network device is not a slave port, comparing the number of forwarding carried in the TLV field received via the port of the network device with the number of forwarding carried in a TLV field received via the slave port of the network device, and if it is judged that the absolute value of the difference between the number of forwarding carried in the TLV field received via the port of the network device and the number of forwarding carried in the TLV field received via the slave port is 0 or 1, selecting a port with the lowest priority as the passive port; and if the port of the network device is a slave port or the absolute value of the said difference between the numbers of forwarding is not 0 or 1, updating clock identifier information of the network device and port identifier information of an Announce packet forwarding port of the network device into the TLV field of the received Announce packet respectively as clock identifier information and port identifier information, and forwarding the updated Announce packet via the Announce packet forwarding port after incrementing the number of forwarding of the Announce packet by one.