HELSINKI — NokiaSiemens Networks defended its decision to sell eavesdropping technology to Iran last year, saying Tuesday it had followed trade rules and acted ethically. Spokeswoman Riitta Mard said the Finnish-German company was surprised over the uproar following allegations that the Iranian government had used the Nokia Siemens Networks technology to monitor mobile phone calls, and possibly e-mails, during the postelection protests.”But that’s all there is to it,” Mard said. “The system (sold to TCI) doesn’t allow monitoring international calls, and it absolutely doesn’t allow monitoring Internet and data communication, not even SMS or picture messages.”