1. How Does MPLS QoS Work?

2. Global Crossing VPN Service – CoS
CoS configuration and capabilities differ for traffic entering the VPN to traffic leaving the VPN
Inbound
Classification of traffic
Maps traffic into the three backbone Class (EF - Premium, AF - Enhanced, BE - Basic) via
Customer Classification using IP Precedence or DSCP code point value in the IP header
Assumes the customer is already using Differentiated Services in their network
Provider Classification using a combination of the following IP header values.
Source Address
Destination Address
Source Port
Destination Port
Protocol
A class classifier will only be provisioned if the customer has subscribed to the class
EF Criteria
Traffic from CPE
Any Combination of class classifiers are supported
EF, AF, BE
EF, AF
EF, BE EF
AF, BE AF BE
AF Criteria
The final (last) classifier does not need any criteria as it will match all remaining unclassified traffic
BE Criteria

3. Global Crossing VPN Service – CoS
CoS configuration and capabilities differ for traffic entering the VPN to traffic leaving the VPN
Inbound
Policing of Traffic
Controls the volume of traffic in each class to a subscribed rate
Known as the Class Subscription Rate or CSR
Sum of the CSR rates must equal the port speed
The class and traffic subscribed to by a customer will dictate if a class policer is configured or not
Allows Global Crossing to control traffic according to 3 traffic models
Usage
Excess EF is Dropped; Excess AF is Dropped; Excess BE is Dropped
EF CSR
Usage
EF Criteria
EF Policer
AF CSR E1
Traffic from CPE
Discard
AF Criteria
AF Policer
BE CSR
Discard
BE Criteria
BE Policer
Discard

4. Global Crossing VPN Service – CoS
CoS configuration and capabilities differ for traffic entering the VPN to traffic leaving the VPN
Inbound
Policing of Traffic
Controls the volume of traffic in each class to a subscribed rate
Known as the Class Subscription Rate or CSR
Sum of the CSR rates must equal the port speed
The class and traffic subscribed to by a customer will dictate if a class policer is configured or not
Allows Global Crossing to control traffic according to 3 traffic models
Usage
Excess EF is Dropped; Excess AF is Dropped; Excess BE is Dropped
Flat Rate
Excess EF is Dropped; Excess AF is marked BE; BE can use Full Port
EF CSR
Flat Rate
EF Criteria
EF Policer
AF CSR E1
Traffic from CPE
Discard
By Full Port we mean that we can receive a full ports worth of traffic for example 2Mb on an E1 for the given class at any instantaneous point in time, as long as no other class traffic is being received at that same point in time.
AF Criteria
AF Policer
BE CSR
Sum of CSR’s = Port Speed
BE Criteria

5. Global Crossing VPN Service – CoS
CoS configuration and capabilities differ for traffic entering the VPN to traffic leaving the VPN
Inbound
Policing of Traffic
Controls the volume of traffic in each class to a subscribed rate
Known as the Class Subscription Rate or CSR
Sum of the CSR rates must equal the port speed
The class and traffic subscribed to by a customer will dictate if a class policer is configured or not
Allows Global Crossing to control traffic according to 3 traffic models
Usage
Excess EF is Dropped; Excess AF is Dropped; Excess BE is Dropped
Flat Rate
Excess EF is Dropped; Excess AF is marked BE; BE can use Full Port
Usage with Burst
Excess EF is Dropped; AF can use Full Port; BE can use Full Port
EF CSR
Usage with Burst
EF Criteria
EF Policer
AF CSR E1
Traffic from CPE
Discard
By Full Port we mean that we can receive a full ports worth of traffic for example 2Mb on an E1 for the given class at any instantaneous point in time, as long as no other class traffic is being received at that same point in time.
AF Criteria
BE CSR
Sum of CSR’s = Port Speed
BE Criteria

6. Global Crossing VPN Service – CoS
CoS configuration and capabilities differ for traffic entering the VPN to traffic leaving the VPN
Inbound
Mark the MPLS Header with relevant CoS value
Allows the entire network to treat the packet based on the Backbone class specified in the classification
Provides Diff Serv transparency.
By not modifying the IP Precedence value the customers marking stay intact
Send to Core with MPLS EXP = Or
Send to egress Customer interface
EF Criteria
EF Policer EF
Traffic from CPE
Discard
AF Criteria
AF Policer AF
BE Criteria BE BE BE

7. Applications – Today and Tomorrow
Intranets – for company communications – LAN extension
Remote access solution for mobile workforce and remote locations
Extranets – for customers, partners, suppliers & communities of interest
Connections to Global Crossing Financial Extranet (content)
Analyst firm – customers download reports, video conferencing & streaming video
Hosted applications
Convergence of applications: voice, video, Internet and corporate data
VoIP
IP Videoconferencing
L2 Virtual Private Lines (VPLs) for legacy protocol transport (X.25, FR/ATM)
Business continuity
Redundant back-up with usage based-billing . . .
. . . also carries your extra traffic

8. Want to Know More? WANT TO KNOW MORE ABOUT OUR SERVICES AND OFFERINGS?
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Headquarters:
Global Crossing
200 Park Ave, Ste 300
Florham Park, NJ 07932