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NOTICE DATE: July 7, 2021

NOTICE TYPE: M-B070721-01 General

SHORT DESCRIPTION: Changes and impacts coming to the Wide Area Network (WAN)

INTENDED AUDIENCE: ERCOT Wide Area Network Participants (QSEs and TOs)

DAYS AFFECTED: July 7, 2021

LONG DESCRIPTION: AT&T has announced END-of-LIFE for the legacy TDM based voice and data transport services. ERCOT will decommission supporting TDM infrastructure beginning January, 2022.

ERCOT is working with Market Participants to upgrade existing WAN (Wide Area Network) locations by replacing the AT&T TDM network with an MPLS and VOIP alternative.

After AT&T disconnects the TDM network, Market Participant locations still using legacy voice systems will no longer have voice communications with ERCOT over the Wide Area Network.

ACTION REQUIRED: Submit upgrade requests prior to 8/1/2021 to allow for completion before AT&T TDM legacy network disconnect.

If you received a “Ready to Schedule” notice from ERCOT ([log in to unmask]), replacement circuits are ready and the migration must be scheduled. Scheduling and preparation instructions are included in the notice.

ADDITIONAL INFORMATION: Partial upgrades have been a recurring issue. A partial upgrade happens when T-Mobile has completed the circuit and hardware activities, but the MP WAN site is not ready to accept the new voice lines.  Double-billing will continue for these locations until AT&T has been disconnected. These locations are also at risk of AT&T disconnect. Please schedule with [log in to unmask] to complete partial upgrades.

Reference Market Notices W-B100119-01 and M-B100119-02 (attached) for additional detail.

CONTACT: If you have any questions, please contact your ERCOT Account Manager. You may also call the general ERCOT Client Services phone number at (512) 248-3900 or contact ERCOT Client Services via email at [log in to unmask].

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