Voice telephony disruptions resolved:O2 mobile network fully available

Read page

O2 Telefónica fully resolved the interim disruption to voice telephony yesterday evening. “Our technical experts reacted immediately and took the necessary measures within a short time to stabilize the network and restore availability. The O2 network is fully available again,” said Mallik Rao, Chief Technology & Information Officer of O2 Telefónica.

Mallik Rao
On Thursday (November 17), there were restrictions in telephony via 2G, 4G and fixed network in the period from about 4 p.m. to 11 p.m. due to a disrupted voice system at a network location. Customers of O2 Telefónica have been able to make full phone calls again since late yesterday evening. Mobile data usage was not affected at any time. Mallik Rao says: “We are very sorry for the inconvenience caused to our customers by yesterday's disruption of voice telephony. Our aim is to provide our customers with a reliable network throughout Germany at all times. They have relied on this every day for years. Yesterday, unfortunately, we did not live up to this claim for a short time. We will analyze the causes in detail and use the knowledge gained to rule out such very rare scenarios as far as possible in the future. We will continue to optimize the network in the interests of our customers and make it the anchor of stability. That is our mission.”

Technical fault triggered by construction work

The technical experts at O2 Telefónica stabilized the network again in a short time.
As part of construction work at a central network location, there was an interruption in the feed line to the voice system at this site, which is responsible for transmitting telephone calls, at around 4 p.m. yesterday afternoon. A large proportion of the calls were initially transmitted via the other voice servers in the O2 network, which are implemented nationwide in the network. Understandably, from this point on customers increasingly attempted to place calls multiple times and re-register their devices in the network. This behavior, which is unusual for the network, ultimately led to further restrictions at the other central exchange points. Due to the restrictions on telephony, some customers were also unable to dial the emergency number. However, there was a basic accessibility of emergency calls or control centers. The technical experts at O2 Telefónica immediately took the necessary measures and successfully stabilized the network again in a short time. Specialists of the company worked together in a very professional and coordinated manner in the central network control center of O2 Telefónica as well as at the network location. The final follow-up work was completed at around 11 p.m. on Thursday.