3Com S7906E Configuration Manual page 351

Feature
QoS
As ONU ports are used for accessing, when the S7900E switch is configured as a DHCP Snooping
device, do not connect a DHCP server to the ONU port.
When an ACL rule is referenced in a QoS
policy, the action defined in the ACL rule
(deny or permit) does not work. Instead, the
action on the packets that match the ACL rule
is determined by the traffic behavior defined
in the QoS policy.
ONU ports support packet filtering based on
source MAC address, destination MAC
address, Ethernet type, VLAN ID, source IP
address, destination IP address, source TCP
port, and source UDP port only.
Source MAC address-based packet filtering
on an ONU port works only on the uplink
direction and supports a maximum of 32 ACL
rules.
Destination MAC address-based packet
filtering on an ONU port works on both uplink
and downlink directions and supports a
maximum of 32 ACL rules.
Ethernet type-based packet filtering on an
ONU port supports a maximum of 30 ACL
rules in the
configuration and a maximum of 16 ACL rules
for each direction when configured for both
uplink and downlink directions.
VLAN ID-based packet filtering on an ONU
port supports a maximum of 6 ACL rules for
the uplink direction and a maximum 8 ACL
rules for the downlink direction.
Source/destination IP address-based packet
filtering on an ONU port supports a maximum
of 24 ACL rules in the case of single-direction
configuration and a maximum of 16 ACL rules
for each direction when configured for both
uplink and downlink directions.
Source TCP/UDP port-based packet filtering
supports a maximum of 24 ACL rules in the
case of single-direction configuration and a
maximum of 32 ACL rules when configured
for both uplink and downlink directions.
6-6
Restrictions
case of single-direction