OBS_VALUE: Telstra has been found to be dominant. Declared fixed line services are mainly supplied by Telstra over its copper public switched telephone network (PSTN) and digital subscriber line (DSL) network at present. Under its structural separation undertaking, Telstra committed to progressively migrating its fixed line voice and broadband customers onto the wholesale-only National Broadband Network (NBN) (https://www.accc.gov.au/publications/telstras-structural-separation-undertaking).Following Telstra's structural separation according to the Migration Plan, the National Broadband Network will take over the lines in most areas. Telstra committed to a structural separation by 1 January 2020 (https://www.telstrawholesale.com.au/about-us/structural-separation-undertaking.html).Since 1 July 2020 the Statutory Infrastructure Provider (SIP) regime has been into force and NBN Co will be the SIP for areas it has declared ready for service. The Minister can equally 'designate' some SIPs and SIP areas (https://www.communications.gov.au/what-we-do/internet/telecommunication-reform-package)