the idle-timeout parameter in ipoe does not work correctly

[turok33gt]

having such an ipoe config, the idle-timeout = 10 parameter does not work, the session always ends after two minutes of no traffic on the interface.

[ipoe]
verbose=10
username=ifname
lease-time=120
renew-time=60
max-lease-time=300
unit-cache=1
shared=0
ifcfg=1
mode=L2
start=dhcpv4
start=up
proxy-arp=2
agent-remote-id=accel-ppp
lua-file=/etc/accel-ppp.lua

vlan-mon=eth0.1155,10-4000
interface=eth0.1155.100
interface=eth0.1155.200,shared=1,giaddr=10.10.10.1,relay=10.10.10.55

local-net=172.16.34.0/24
gw-ip-address=172.16.34.1/24

vlan-timeout=300
vlan-name=%I.%N
ip-unnumbered=1
idle-timeout=10

ipoe0 | eth0.1155.200 | f0:1f:af:1c:bb:8b | 10.10.10.3 | 10000/10000 | ipoe | | active | 00:01:59
root@Video-Accel:/opt/accel-ppp/build# accel-cmd show sessions
ifname | username | calling-sid | ip | rate-limit | type | comp | state | uptime
--------+---------------+-------------------+------------+-------------+------+------+--------+----------
ipoe0 | eth0.1155.200 | f0:1f:af:1c:bb:8b | 10.10.10.3 | 10000/10000 | ipoe | | active | 00:02:01
root@Video-Accel:/opt/accel-ppp/build# accel-cmd show sessions
ifname | username | calling-sid | ip | rate-limit | type | comp | state | uptime
--------+----------+-------------+----+------------+------+------+-------+--------