M. Dinesh Varma

CHENNAI: BSNL’s mobile services were disrupted for hours on Thursday after a switching unit on Haddows Road developed a software hitch.

Though the other four switching units in the city remained functional, the repeated attempts by hundreds of mobile users trying to get their call through took a toll on the entire network, BSNL officials said.

Chennai Telephones has over nine lakh users, with roughly a third of them parented to Haddows Road switching unit.

This “artificial traffic”, which invariably follows a logistic hitch anywhere in the network, seriously choked the CellOne system and lowered the rate of successful calls, sources said.

It is estimated that only one of every call made to a BSNL mobile number eventually got through in what turned out to be a contrived peak load situation.

A BSNL official said the system was restored by afternoon, but cautioned that it would take a few hours more for the network to stabilise.

Meanwhile, an official said technical crew have more work to do on the BSNL’s Mobile Switching Unit in Coimbatore that had developed “electrical problem” on Wednesday. After mobile users parented to the MSU blacked out, officials undertook “emergency routing” of several calls.

Though the MSU was temporarily restored, a few remaining problems will be sorted out on Thursday night, an official said.

Consumer activist T. Sadagopan said mobile users remain in the dark whenever the network develops a glitch. The BSNL should establish an information point that is more responsive than existing customer care centres, he said.