ARRIS G36 – Slow upload speeds

Hello Xfinity Support,

I'm experiencing an upload speed issue that appears nearly identical to the issue described in this thread:

https://forums.xfinity.com/conversations/your-home-network/arris-g36-slow-upload-speeds/69d076fbc7e6ed1c28ceee62

Current setup:

• Internet plan: 1 Gig Download / 1 Gig Upload

• Modem/router: ARRIS SURFboard G36 (DOCSIS 3.1)

• Connection: PC connected directly to modem/router via Ethernet

Speed test results:

• Download: ~551 Mbps

• Upload: ~41 Mbps

I found the previous G36 discussion particularly concerning because the customer experienced very similar symptoms where the upload speed seems to be consistently around 40 Mbps instead of the expected 100+ Mbps. In that case, Xfinity eventually confirmed that the G36 was receiving an incorrect DOCSIS BOOT/configuration file. 

This has been an on going issue for months of troubleshooting on my end, so as a last resort I am reaching out here. 

Thank you in advance for your help!