The process of using WiFi calling can slow down your cable modem's internet speed.
The process of using WiFi calling can slow down your cable modem's internet speed.
I previously had a stable 20 Mbps upload speed but now it's only 5 Mbps. I need help improving my slow upload performance. I contacted my ISP, who suggested replacing my old router with a new one, but I'm still experiencing the slow speed even when no one is using the internet.
So if your device with WiFi calling enabled is disconnected, you do not have the problem? Also are the other devices WiFi or wired? I wonder if WiFi calling might limit the WiFi upload speed for all WiFi devices in some cases, in which case it shouldn't impact wired devices.
ISP problems with speeds often stem from several factors. RF interference is common, especially when using frequencies between 5 MHz and 42 MHz. Power levels should ideally sit between 35 dB and 47 dB according to Docsis 3.1 standards. Network congestion is another concern—check how many upstream channels your modem can access. While Docsis 3.1 models typically offer 8 channels, some lower-end units may have only 4. In my area, Comcast has added a fifth upstream channel to ease congestion. Remember, everyone shares the same node; higher usage affects performance more. I’m not sure if Cox plans to upgrade Docsis to Docsis 4 or implement mid-splits for faster uploads. Comcast may eventually raise upload speeds to 75 Mbps up to 200 Mbps based on your plan.
Might be a QoS rule in your router that gives priority to VoIP calls
You weren’t anticipating a decrease in upload speed when sending data. For VoIP calls, your upload usage will use the available bandwidth. At the conclusion of the call and once network activity drops, your full upload capacity should resume. Some routers struggle with VoIP traffic, causing delays for other users. If your router offers QoS or Smart Queues, enable them. In the first case, prioritize VoIP through TCP/UDP port 5060 or assign a specific client/MAC/IP/app higher bandwidth. I’ve learned that Grandstream APs and routers handle VoIP traffic effectively.