Meaning of ER in English
Explicit Rate: The Explicit Rate is an RM-cell field used to limit the source ACR to a specific value. It is initially set by the source to a requested rate (such as PCR). It may be subsequently reduced by any network element in the path to a value that the element can sustain. ER is formatted as a rate.
ATM Forum English vocabulary. Английский словарь организации Форум ATM. 2012