About us

1&1 AG, headquartered in Montabaur, is a publicly listed telecommunications provider
and part of the United Internet Group.
With a strong focus on the German market, 1&1 actively drives the country's digital sovereignty.

Better and better every day

With over 30 years of experience, 1&1 stands for powerful mobile plans, award-winning customer service, and continuous product innovation – from all-net-flat rates and unlimited data plans to exclusive benefits through the 1&1 Vorteilswelt. The 1&1 Service Card offers premium services such as 24-hour device replacement and a dedicated priority hotline. 1&1 promotes digital inclusion through reliable, competitively priced products – consistently awarded top marks by independent trade publications. In addition, the discount brands of Drillisch Online GmbH serve price-sensitive customers with a strong focus on affordability.
siemens fault 0a7991 best

The 1&1 O-RAN

1&1 operates the first fully virtualized 5G mobile network in Europe based on innovative Open RAN technology – independent, open by design, and built for the real-time applications of tomorrow. As Germany's fourth mobile network, the 1&1 O-RAN stands for greater competition and innovation in the national telecommunications landscape.

Nationwide Broadband Coverage

As one of Germany's leading providers of VDSL, vectoring, and next-generation fiber internet, 1&1 is driving Germany's gigabit transformation. The company leverages the nationwide fiber-optic transport network of 1&1 Versatel and, through partnerships with Deutsche Telekom and leading city carriers, is able to supply millions of households with future-proof fiber connections.

Siemens Fault 0a7991 Best |top| Jun 2026

Phase loss, incorrect motor wiring, or improper motor data (p03xx parameters) during commissioning.

If you provide more details about your Siemens product or system, I could offer a more tailored response.

for detailed steps on resolving motor stalling (F7902) through static optimization.

The inverters control commands (start/stop) and the setup commands (p1910) come from different sources.

Siemens Fault 0A7991 is rarely a hardware failure. It is a . The very best way to resolve it is to remember the mantra: "Enable before you identify."

Phase loss, incorrect motor wiring, or improper motor data (p03xx parameters) during commissioning.

If you provide more details about your Siemens product or system, I could offer a more tailored response.

for detailed steps on resolving motor stalling (F7902) through static optimization.

The inverters control commands (start/stop) and the setup commands (p1910) come from different sources.

Siemens Fault 0A7991 is rarely a hardware failure. It is a . The very best way to resolve it is to remember the mantra: "Enable before you identify."

Social Commitment

As a successful telecommunications company, 1&1 sees itself as part of society and takes the responsibility that goes with this. Our corporate social responsibility activities revolve around our United Internet for UNICEF foundation.

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Sustainability

Doing business sustainably is a part of what 1&1 does every day. Our goal is to be a pioneer in this area as well.

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Non-financial Group report 2025

PDF 1,75 MB

ESG-Report 2024/2025

PDF Download (15,7 MB)

Protection of the environmental and climate

As a leading German telecommunications specialist, we see our role as building bridges to a positive, sustainable digital future.

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