User's Manual

Table Of Contents
361
Users Manual of CS-6306R
37.3.1 Creating the Transparent Clock Port
The transparent clock can include multiple PTP ports to connect the master and slave clock respectively.
Run the following commands in port configuration mode to create the PTP ports:
Command Purpose
ptp start l2
Creates the PTP L2 port.
Ptp start l3
Creates the PTP L3 port.
Run the following command in port configuration mode to delete the PTP ports:
Command Purpose
no ptp start
Delete the PTP port.
37.3.2 Configuring the Link Delay Calculation Mode
The PTP transparent clock supports two link delay modes (E2E and P2P) to help the master and slave clocks
switch between the two modes, among which P2P is the default mode. In E2E mode, TC can process
Delay_Req,Delay_Resp packets; In P2P mode, the path-delay mechanism is running on each PTP port, the
Pdelay_Req packets are transmitted periodically, and the Pdelay_Resp and Pdelay_Resp_Folllow_Up
packets are responded to. The two modes are incompatible with each other. For example, if it is in P2P mode,
the Delay_Req packets received from the clock will be dropped.
Run the following command in global configuration mode to configure an authentication mode:
Command Purpose
ptp delay-mechanism e2e Sets TC to work in E2E mode.
To configure the authentication mode, you also can run the following command in interface configuration
mode:
Command Purpose
ptp delay-mechanism p2p Sets TC to work in P2P mode.
37.3.3 Configuring the Forwarding Mode of Sync Packets
There are two ways to forward Sync packets: straight forwarding and store-forward.
In straight forwarding mode, the PTP port immediately forwards after receiving Sync packets, re-encapsulates
the Follow_UP packets after receiving them and then forwards them out from the corresponding port.
In store-forward mode, the PTP port shall not forward Sync packets after receiving them but store them first,
receive corresponding Follow_up packets and then forward the two kinds of packets together.
The straight forwarding mode is the default one. In this mode, the time to handle Sync packets is apparently
less than the time to handle Follow_up packets and hence in case of multi-level TC cascading the risk of
packet disorder arises. That’s why the store-forward mode is recommended in case of multi-level TC
cascading. However, in normal cases, we recommend the straight forwarding mode for it can lessen the
residence time of Sync packets at the maximum level and reduce its impact on time synchronization.
Run the following command in global configuration mode to configure an authentication mode:
Command Purpose