Issue with ePTP Mode on Cambium 4600c Causing OSPF Instability

[Jonathan_Solutions (Jonathan Mendez)]

Hi everyone,

I’m experiencing an issue with several Cambium 4600c links operating in the 6 GHz band. My network consists of both long links (up to 100 km) and short links (around 3 km), all running on the TDD driver without major issues.

However, when I try to switch shorter links to ePTP mode to increase capacity, I notice that OSPF state changes become unstable, reaching up to 92 changes instead of the usual 4-5 seen on a stable link. Additionally, OSPF adjacencies drop every few hours, causing network disruptions.

This issue occurs regardless of link distance, whether it’s 3 km or even 32 km (which I understand is the limit for ePTP).

I have tested all firmware versions from 5.4 to 5.9.1, and the problem persists in all of them. The issue also happens with different antenna brands and models, including those specifically designed for 6 GHz operation.

Has anyone else experienced this? Any recommendations or insights would be greatly appreciated.

Thanks!

[Eric_Ozrelic]

Take a look at this post, you may need to disable the acceleration engine.

4600 ptp data dropping?

We have an existing ptp 450i we are trying to replace with a pair of 4600 for more capacity. The original 450i link has been in place for a couple of years with no issues. When we try to insert the new 4600 ptp’s (which are running 80mhz in 6ghz with 500/500 link test) the customers immediately complain of poor loading of web pages and speed tests do not work. we swap the radios back and problem immediately goes away. The link is set up in eptp mode, i have tried 5.8, 5.9 and 5.9.1beta with…

[aka (Andrii)]

Hello @Jonathan_Solutions,

we have a potential fix for such OSPF drops. It is merged in alpha release. Pleas, PM me if you would like to try it!

[Jonathan_Solutions (Jonathan Mendez)]

@Eric_Ozrelic

Take a look at this post, you may need to disable the acceleration engine.

Thanks. I will try that and comeback with the feedback

@aka

Hello @Jonathan_Solutions,

we have a potential fix for such OSPF drops. It is merged in alpha release. Pleas, PM me if you would like to try it!

Seems like I cant PM anyone yet, but I would like to try that. Could you PM me instead?

[Jonathan_Solutions (Jonathan Mendez)]

I’m leaving some feedback on this issue.

I’ve changed the Acceleration Engine to valor=3 on every 4600c radio in my network, and they have been working significantly better for the past month.

This seems to have been the root cause of the problem, as I no longer experience OSPF adjacency losses. The improvement is noticeable regardless of whether the radios are using the TDD driver or the ePTP driver.