To meet the stringent performance requirements of PTP mobile network applications, the 1588 packets must be time-stamped and the ingress and egress ports. This requires the use of 1588 port-based timestamping on the ports handling the PTP messages. This avoids any possible PDV that may be introduced between the port and the CPM. The ability to timestamp in the interface hardware is provided on a subset of the IMM and MDA assemblies of the routers. Generally, all FP4-based XMA, XMA-s, and MDA-e-XP modules support 1588 port-based timestamping. For other assemblies, contact your Nokia representative to verify the support for 1588 port-based timestamping.
In order for this to operate, the CPM, IOM, IMM, and MDAs must be running firmware that supports this capability. The CPM firmware upgrade occurs automatically when the CPM card software is updated. Because upgrading IOM, IMM, and MDA firmware is service impacting, this upgrade is not performed automatically on a soft reset of the MDA. The IOM/IMM firmware is upgraded when the IOM/IMM card is hard reset. The MDA firmware is programmed during system initialization, when the MDA is inserted, or when the MDA is hard reset via a clear mda or clear card command. However, when an MDA is soft reset via either a clear card soft command or during a major ISSU, the MDA firmware is not updated.
Port-based timestamping of 1588 packets cannot be used at the same time for Ethernet encapsulation and IP encapsulation on a specific port. This means that PTP cannot be configured on an Ethernet port if ptp-hw-assist is already configured on a Layer 3 interface associated with that port. Similarly, ptp-hw-assist cannot be configured on a Layer 3 interface if its associated port is already configured as a PTP port.