Jan 30, 2023

CB 350

Some customers have experienced issues with POE and IPT’s on 8+2 port CBS 350 switches.

The switch logs show over current errors when power cycling switches or IPT’s and or resetting the Clear-Com frame, this causes the POE to be shutdown and the switch-port is left in a fault state.

Recovering could be achieved by toggling off and on the POE on the switch-ports in question.

Cisco CBS 350 Switch firmware 3.2.0.89 appears to solve the problem

Nov 11, 2024

From Cisco blog

CBS350 AES67 PTPv2 Jitter Under Load

We have a few vlans setup to keep AES67 traffic separate from the Dante traffic. Switches are connected via Trunks. QOS is enabled and configured for AES67 networks. 

When the switches have low load (very few devices connected) PTPv2 timing is spot on across devices on the network. If we take ~20 Dante POE devices and connect them to one of the CBS350-24P-4G switches, the AES67 devices (2) on that switch start drifting as much as 1.5ms from the GM and loose sync. If we move the ~20 Dante devices to the other switch then we see that switch settle down and the new switch with the high device count starts to drift off the network. 

Some notes / observations:

• All switches are running current firmware and have been factory reset.

• There are no dropped packets in the QOS Queue log.

• At no point does any interface get above 8% utilization.  

It almost feels like the switch is not fast enough when switching large number of devices.