When Optus provide details for a new internet connection they may be displayed in the below format. Bit confusing as CE\PE Wan is used as MPLS : 

Circuit ID : XXXXXXXXXXXX

THIS is your main Gateway

CE WAN IP : XXXXXXXXXXX

THIS is your main Address Block 

PE WAN IP : XXXXXXXXXXXX

Subnets Marks : 255.255.2555.252

THIS is your additional Address Block 

Requested /29 Global Ip Address Scope 

Order Reference : XXXXXXXXXXXXXXXXXX

CE WAN IP : XXXXXXXXXXX

PW WAN IP : XXXXXXXXXXXX

Subnets Marks : 255.255.2555.248

THIS is your main Address Block 

Usable IP Range : XXXXXXXXXX to XXXXXXXXXXXX