Part of Cambridge’s fire infrastructure that does not rely on cell signal. (Photo: City of Cambridge)

The 911 emergency dispatch system suffered problems statewide Friday that also hit Cambridge and Somerville.

The problem affected primarily the operations of call centers, hindering the ability of dispatchers to log into the 911 system. Calls were dropped or rerouted to the wrong dispatch center before service was restored, said officials with the cities. Cambridge suffered sporadic problems for a little under five hours, from around 11 a.m. to 3:45 p.m.

Cambridge residents were advised to use non-emergency numbers instead of dialing 911 – those are (617) 349-3300 and (617) 864-1212 – in bulletins via Cambridge’s Tip411 system, email and social media accounts for police and fire departments. The Cambridge Fire Department reported that the Emergency Communications Center was experiencing problems with “users not being able to log in to access 911 and/or intermittent dropped calls.”

“We did not know the cause of the outage,” Cambridge police spokesperson Robert Goulston said Friday. “State 911 Department did not provide any details.”

While a few calls dropped during the time of the signal problem, residents “were able to call us back and connect,” Goulston said. “There were no delays or impediments to responses to calls during this time.”

The State 911 Department and Cambridge have continuity planning in place if issues such as Friday’s are encountered, he said. Each 911 center has backups, so if one encounters a problem, the state can reroute calls. “We also monitor our 911 system in the center for any disruptions. If any issue is identified, a report is made” to a help desk that has vendor support around the clock, Goulston said. “If there are system issues, the City of Cambridge immediately notifies residents of the issue, provides alternate non-emergency, emergency numbers and reminds residents of the fire boxes, as we did today.”

Fire boxes at every firehouse in Cambridge and at several other locations are another option in a situation in which 911 goes down, the fire department said. The fire boxes are connected directly to the Emergency Communications Center without the use of cell signals, and are therefore available in case of cell service outages. Fire box calls will also bring police.

Somerville police and fire were affected briefly by the outage, city spokespeople said.

The problem stretched as far as Springfield, “one of several communities that were impacted by a 911 problem Friday morning,” according to the Western Mass News.