In a fronthaul network comprising a radio equipment controller connected to a proxy slave, a proxy master connected to a radio equipment, and an Ethernet network connecting the proxy master and the proxy slave, a method for establishing a Common Public Radio Interface, CPRI, link between the radio equipment controller and the radio equipment over the Ethernet network, the method comprising: receiving, at the proxy slave from the radio equipment controller, a first CPRI bit stream transmitted at one or more first link bit rates at one or more respective transmit times, and attempting to decode, at the proxy slave, the first CPRI bit stream at one or more second link bit rates at one or more respective reception times, wherein the link bit rates are line bit rates; on achieving hyper frame number synchronization, HFN Sync, between the proxy slave and the radio equipment controller at a link rate, hereinafter referred to as sync link bit rate, mapping the first CPRI bit stream to one or more Radio over Ethernet, RoE, frames; wherein at least one of the one or more RoE frames comprises a header indicating the sync link bit rate; transmitting the one or more RoE frames to the proxy master; on receiving one or more RoE frames from the proxy master, wherein the one or more RoE frames received from the proxy master comprise a second CPRI bit stream transmitted by the radio equipment, de-mapping the one or more RoE frames received from the proxy master; transmitting the second CPRI bit stream to the radio equipment controller at the first sync link bit rate; and upon HFN Sync being achieved between the proxy slave and the radio equipment controller using the sync link bit rate, communicating between the radio equipment controller and the radio equipment via the established CPRI link using the sync link bit rate. receiving, at the proxy slave from the radio equipment controller, a first CPRI bit stream transmitted at one or more first link bit rates at one or more respective transmit times, and attempting to decode, at the proxy slave, the first CPRI bit stream at one or more second link bit rates at one or more respective reception times, wherein the link bit rates are line bit rates; on achieving hyper frame number synchronization, HFN Sync, between the proxy slave and the radio equipment controller at a link rate, hereinafter referred to as sync link bit rate, mapping the first CPRI bit stream to one or more Radio over Ethernet, RoE, frames; wherein at least one of the one or more RoE frames comprises a header indicating the sync link bit rate; transmitting the one or more RoE frames to the proxy master; on receiving one or more RoE frames from the proxy master, wherein the one or more RoE frames received from the proxy master comprise a second CPRI bit stream transmitted by the radio equipment, de-mapping the one or more RoE frames received from the proxy master; transmitting the second CPRI bit stream to the radio equipment controller at the first sync link bit rate; and upon HFN Sync being achieved between the proxy slave and the radio equipment controller using the sync link bit rate, communicating between the radio equipment controller and the radio equipment via the established CPRI link using the sync link bit rate.