Downstream traffic can be subjected to aggregate rate-limit per tunnel or per tunnel and per retailer combination (in case of wholesale). Typically a unique SSID is used per retailer for wholesale on the AP and is reflected via unique dot1Q tag. With a wlan-gw tunnel per AP, the tunnel encapsulation is performed on the tunnel ISA. The downstream traffic on the tunnel IOM is received over B-VPLS from the anchor IOM, and is MAC-in-MAC (802.1ah) encapsulated. I-SID in the packet represents the GRE tunnel or tunnel and retailer combination. SAP-egress QoS policy defining queues (with rates), and FC to queue mapping, can be specified under the wlan-gw interface. This policy is applicable to all tunnels (or tunnel and SSID combinations) associated with the wlan-gw interface and is attached to corresponding I-SIDs on the B-VPLS SAP. Traffic is shaped into these queues based on configured queue rates. An aggregate rate-limit applied across queues on an I-SID (representing tunnel or tunnel and retailer combination) can be configured under the wlan-gw interface (represented by the wlan-gw node under the group-interface configuration). The aggregate rate-limit works in conjunction with a port-scheduler. The port-scheduler corresponds to the internal port between tunnel ISA and its carrier IOM and is specified at the wlan-gw IOM group level. The rate-limit includes the B-VPLS encapsulation overhead. The configuration is shown in Figure: EAP authentication call flow with WLAN-GW RADIUS proxy. Queues per I-SID also work with virtual-scheduler (with or without a port scheduler). Virtual-scheduling and aggregate-rate enforcement are mutually exclusive. Configuration is shown in Figure: Portal authentication for open SSIDs. Egress SAP QoS policy, aggregate rate-limit, port-scheduler, and virtual-schedulers are described in the 7450 ESS, 7750 SR, 7950 XRS, and VSR Quality of Service Guide. The SAP egress QoS policy associated with a wlan-gw interface implicitly creates queues (and scheduler association) on ISIDs as corresponding wlan-gw tunnels are created. General ISID queuing and shaping is defined in the SR OS Services Guide.
A configuration node under wlan-gw interface (egress) controls where the egress shaping is applied and can specify either tunnel or retailer (tunnel and retailer combination in case of wholesale). Per I-SID shaping resources can be held after the last subscriber on the tunnel is deleted, for a configurable amount of time (hold-time) configured under the wlan-gw interface. During ISA or IOM failover the tunnel resources on the IOM kept because the hold-time are reclaimed. ISID shaping can be configured (via knob shape-multi-client) to be applied only when there is more than one UE on the corresponding tunnel (or tunnel and retailer combination). A total of 40,000 shaped tunnels (or shaped tunnel and retailer combinations) are supported per WLAN-GW IOM. Hardware resources for tunnel (ISID) shapers are shared with subscribers. With 3 WLAN-GW IOMs per chassis, a maximum of 98,000 (3 *64K / 2) shaped tunnels and subscribers can be supported per chassis.
The following output depicts per tunnel or per tunnel/SSID egress QoS (with aggregate-rate and port-scheduler).
// Port-scheduler
config>qos#
port-scheduler-policy ‟lo-gre-port-sched”
max-rate 5000
level 1 rate 1000 cir-rate 1000
level 8 rate 500 cir-rate 500
exit
exit
// Egress queues (per ISID) parented by port-scheduler specified under associated wlan-gw interface
config>qos>
sap-egress 3 create
queue 1 create
rate 300
port-parent level 1 weight 10 cir-level 1 weight 10
exit
queue 2 create
rate 100
port-parent level 8 weight 10 cir-level 8 weight 10
fc af create
dot1p 2
de-markweight
exit
fc be create
queue 1
dot1p 0
de-mark
exit
fc ef create
queue 2
dot1p 5
de-mark
exit
exit
exit
// The wlan-gw interface refers to SAP egress QoS policy and aggregate rate-limit for associated ISIDs
config>service>ies>sub-if>grp-if>wlan-gw>egress
agg-rate-limit 2000
hold-time 300
qos 3
shaping per-tunnel
shape-multi-client
exit
// Port-scheduler parenting queues (per ISID)
Per Tunnel or Per Tunnel/SSID Egress QoS (with aggregate-rate and port-scheduler)
config>isa>wlan-gw-group#
active-iom-limit 1
tunnel-port-policy "lo-gre-port-sched"
iom 2
iom 3
no shutdown
exit
The following output depicts per tunnel or per tunnel/SSID egress QoS (with virtual-scheduler).
// hierarchical virtual scheduler
config>qos#
scheduler-policy ‟virtual-sched-policy”
tier1
scheduler ‟all-traffic” create
rate 10000
exit
exit
tier2
scheduler ‟non-voice” create
parent all-traffic cir-level 1
rate 9000
exit
scheduler ‟voice” create
parent all-traffic level 2 cir-level 2
rate 3000
exit
exit
exit
// egress queues (per ISID) parented by virtual scheduler
config>qos>
sap-egress 3 create
queue 1 create
parent ‟non-voice”
rate 2000 cir 1000
exit
queue 2 create
parent ‟voice”
rate 500 cir-rate 500
fc be create
queue 1
dot1p 0
de-mark
exit
fc ef create
queue 2
dot1p 5
de-mark
exit
exit
exit
// A wlan-gw interface refers to SAP egress QoS policy and hierarchical scheduler for associated ISIDs
config>service>ies>sub-if>grp-if>wlan-gw>egress
hold-time 300
qos 3
scheduler-policy ‟virt-sched-policy”
shaping per-tunnel
shape-multi-client
exit