Uninterruptible Power Supply Degrades Network and DSL Speeds
Uninterruptible Power Supplies (UPS) frequently provide network (RJ45) and/or telephone cable (RJ11) jacks which allow those cables to be protected from power surges and other problems. However, generally the UPS will degrade the signal on the cable to the extent that 1000Mbit (1Gbit, Gigabit) ethernet connections are not attainable on network cabling, nor ADSL2-equivalent line sync across telephone lines. However, 100Mbit and low-speed DSL (approx 1Mbit) will be attainable.
If you need Gigabit ethernet and/or the fastest DSL signal the line is capable of, do not route them through the UPS or power protection board. Attach the cables directly between the computer/switch or DSL modem and telephone socket.