Foundry NetIron M2404C and M2404F Metro Access Switches
Configuring HQoS (Rev.03)
Carrier Grade Ethernet Services and HQoS
© 2008 Foundry Networks, Inc.
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10Mb/s
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Figure 5: Multi-Office SLA
Example 3: Multi-Service SLA
In this example a customer is subscribed to two or more services, e.g. VPN and DIA (Direct
Internet Access). All the customer’s traffic flows through the same UNI and services are
differentiated using EVCs. The VPN service has a higher priority and CIR, while the entire
customer’s traffic is limited by customer-level CIR. If the VPN CIR is 8Mb/s and the customer’s
CIR is 10Mb/s, then if VPN currently uses 5Mb/s only, the DIA traffic can burst to use up to
5Mb/s without losing packets.
10Mb/s
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Figure 6: Multi-Service SLA
In all the examples presented above, had the ‘flat’ QoS model been implemented, the lower
priority traffic would be much more limited, as it could not make use of the bandwidth unused by
the other applications/services, but still available to the customer. Thus, the HQoS model enables
enhanced services, with flexible SLAs and better bandwidth utilization. The better bandwidth
utilization allows the carrier to sell its available bandwidth to more customers (usually more
profitable than selling more bandwidth to each customer), while it also allows each customer to
save on bandwidth expenses.
By implementing a true HQoS model, the device enables the carriers to significantly enhance their
service offerings and enjoy the benefits described above.