NOTICE DATE: March 21, 2017

NOTICE TYPE: W-A032117-01 Operations

SHORT DESCRIPTION: Upcoming changes to ERCOT’s Wide Area Network

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

DAY AFFECTED: March through December 2017

LONG DESCRIPTION: ERCOT plans to upgrade its Wide Area Network (WAN) transport infrastructure and prepare for a planned change in technology by Sprint, ERCOT’s WAN management service provider, during the remaining months of 2017. The changes will address end-of-life and end-of-support issues for hardware related to ERCOT’s WAN as well as prepare for a change in Sprint’s WAN service from Time Division Multiplexing (TDM) to an Ethernet based network service after March 2018.

ERCOT has been planning for the hardware upgrade and technology changes over the last few months. ERCOT has started preparatory activities during March 2017 at its headquarters in Taylor, TX and Bastrop, TX that require no action to be taken by WAN Participants (Qualified Scheduling Entities (QSEs) and Transmission Service Providers (TSPs)).

The remaining steps required to complete the change in technology will require coordination between ERCOT and WAN Participants. The plan to be executed over the next several months includes:

· Upgrade of ERCOT’s WAN service at its headquarters in Bastrop, TX and coordination of required WAN outage (Currently planned for April 2017)

· Upgrade of ERCOT’s WAN service at its headquarters in Taylor, TX and coordination of required WAN outage (Currently planned for May 2017)

· Upgrade of WAN service at each WAN Participant site and corresponding changes to WAN invoices due to the change from TDM Access delivery to Ethernet Access delivery (Currently planned for June 2017 through December 2017)

ERCOT will send follow up Market Notices with exact dates of outages and details of impacts to WAN Participants.

Please forward this market notice to those in your organization charged with maintenance of the ERCOT WAN interface and need to know about the upcoming changes described above.

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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