SIP Code 603 'Most Pragmatic Solution': USTelecom

Session initiation protocol 603 is “the best and most pragmatic solution to provide callers with actionable information,” said USTelecom in reply comments to the FCC’s Further NPRM on call blocking notifications Tuesday in docket 17-59 (see 2202010031). SIP code 603 is a "pragmatic and effective means of providing immediate notification," said AT&T, and SIP code 607 is "unnecessary." Verizon backed mandating 603 “when terminating service block calls based on analytics.” Efforts to improve redress processes “should continue to be left to the industry stakeholders to address,” said Transaction Network Services, saying 603 “provides sufficiently actionable information.” The Voice on the Net Coalition, Incompas and Cloud Communications Alliance disagreed, saying “failure to implement SIP codes 607 and 608 will result in legitimate calls being blocked and in onerous redress processes.” The groups backed phasing out the use of 603. SIP code 603’s “lack of specific, actionable information makes it an unsustainable long-term option,” said TCN. “Additional standards body work could clarify questions raised and resolve technical issues that remain” for all three codes, said NTCA.