Leased Line - Cisco Firmware

We have a 100Mbit over 1Gbit bearer leased line terminated into an ADVA FSP 150-GE102 Pro, connected to a Cisco C1117-4P. The only equipment we manage is everything behind the Cisco, including our DrayTek 2927 router which connects into LAN1 on the Cisco.

The firmware version running on the Cisco is 17.5.1a:

https://software.cisco.com/download/home/286315006/t...

Since the service went live, our ISP has never pushed software updates to the Cisco and from what I can see, Cisco are promoting version 17.6.5 as being the better firmware. We're having on-going issues with certain websites and services running unbearably slow, that run perfectly fine over any other connection, including 1-bar 4G mobile data.

Speed tests show full speeds, but I believe there's some sort of routing issue happening, and I wondered if these sorts of issues can happen with certain firmware, or even be improved/resolved with newer firmware?

I've never seen an ISP proactively update software on CPE like that.

It may even be that they aren't eligible for upgrades from Cisco dependent on the status of the contract (or even if they have one) with Cisco.

To be honest, it's unlikely that an upgrade would solve your issue...all you can do is hassle the ISP.

I would suggest you take up the issues directly with your service provider, as it’s a managed service. You don’t need to be “in the weeds” so to speak diagnosing potential Cisco firmware issues as it’s their box to manage.

The service to you is what matters and if that’s not working as expected push it back to them to sort. That’s what you’re paying them for.

If you are referencing your OneDrive speed issues from this thread then it's not clear that you've bypassed your DrayTek router yet. In fact it seems like you're trying to do everything *except* bypass that, even going as far as to presumably reboot your managed router with a console cable plugged in to get the IOS version.

Why don't you revisit your original thread and pick up where you left off?

Unless the Cisco is doing something application layer it shouldn't change anything on one website vs another. That's more likely to be ISP core network related.