Andrew, a vendor representative, told the ESInet users group that several PSAPs have reported incomplete automatic-location-identifier (ALI) information since Verizon migrated traffic from SS7 to SIP, and he described how header changes are affecting data delivery.

The issue matters because ALI information helps call takers locate callers during 911 incidents; incomplete data can impede response.

Andrew said the header behavior changed when Verizon moved to SIP and that the cellular callback number and other ALI-related fields are now arriving in different SIP headers. “The Verizon, changed to SIP, the p Annie in the from and is in the from and PAI headers. When they switch to SIP, Verizon is sending the cellular callback number in the PAI, but still sending the p annie in the from field,” Andrew said. He offered to share technical details with any PSAP experiencing the problem and to help troubleshoot vendor configurations.

Alex with Wesco flagged regional impacts in the chat, saying Delta and Gunnison reported being affected. Participants said Lumen and other CPE vendors have already corrected some customer sites and that PSAPs should contact their vendors if they see missing ALI on Verizon Wireless calls.

The group discussed documenting the root cause and adding guidance to the shared tracker so all PSAPs can check whether they are similarly affected. No formal action or statewide fix was adopted during the meeting; vendors and PSAPs will continue direct troubleshooting and will share corrective steps when available.