The April 9 rally, along with a planned showdown at AT&T’s upcoming annual meeting at the end of the month in Dallas and other future actions, comes after a one-day grievance strike on March 22 and tense negotiations for a new contract covering about 17,000 workers in the company’s traditional wired telephone business.

The AT&T employees—mostly technicians and call center workers in the Communications Workers of America union—are pressing for better wages and healthcare benefits along with an end to outsourcing of jobs to nonunion workers, sometimes outside of the United States. But AT&T is under pressure to cut costs in the shrinking telephone business. And the carrier is also negotiating with 21,000 CWA workers in its wireless business whose contract expired in February.

Unlike competitor Verizon, which was hit with a bitter seven-week strike last year, AT&T has seen a lengthy period of constructive dealings with the CWA and other unions. Since the start of 2015, AT&T has completed 28 straight deals with its unions, covering 123,000 workers. The last strike over a contract at the company was in 2012, and just for two days.

Also, the California and Nevada workers, who service AT&T’s telephone, cable and Internet services, have had difficult talks in the past. The prior contract also took over a year to ratify. This group of workers “is an outlier, and lengthy negotiations are not unusual for them,” a spokesman for AT&T said.

Still, labor relations have been getting increasingly tense in the telecommunications industry since the Verizon strike resulted in higher pay and better job security for unionized workers there. In addition to rising tensions at AT&T, the CWA is ramping up efforts to unionize workers at T-Mobile (TMUS). A judge at the National Labor Relations Board rebuked the carrier this week for forming an illegal management-controlled labor group. The company said it will appeal the ruling.

Get Data Sheet, Fortune’s technology newsletter.

On Wednesday, AT&T union member Armando Zepeda wrote a post on Medium explaining the one-day grievance strike, which was due to AT&T changing work assignments of some unionized technicians, and complained the the company was dragging its feet in the larger contract negotiations.

“We are emboldened by our successful strike and we will do what it takes to settle our contract,” he wrote.

The 17,000 workers overwhelmingly voted in February to authorize a full strike over the contract, but union negotiators have said they aren’t at that stage yet.

AT&T (T) officials say that the company has offered annual wage and pension benefit increases in the latest negotiations. The healthcare plans offered to the landline workers, they continued, are similar to what employees across the country have received in other contracts. “We’re confident employees will be better off financially in their new contract,” a spokesman said.