The format used by the client for the Connect-Info attribute
(attribute number 77):
default The Connect-Info Attribute is generated from the
underlying interface id string.
l2tpConnectSpeed The Connect-Info Attribute is generated from
the received l2tp connect speed AVPs. The format
is in bits per second:
<tx-connect-speed>[/<rx-connect-speed>]
The receive connect speed is included if non
zero and different from the transmit connect speed.
l2tpConnectSpeedRXWhenEqual
The Connect-Info Attribute is generated from
the received l2tp connect speed AVPs. The format
is in bits per second:
<tx-connect-speed>/<rx-connect-speed>
The receive connect speed is included if non-zero.