LT2P, among other attributes, also passes the attributes with the connected speed
Information of AV Pairs: https://www.iana.org/assignments/l2tp-parameters/l2tp-parameters.xhtml#l2tp-parameters-1
- Attribute type = 24 --> Description: (Tx) Connect Speed BPS AVP
- Attribute type = 38 --> Description: Rx Connect Speed AVP
If possible, these attributes should be passed to Radius Server