The test plan covered the following topics of interoperability:

 

Video over DSL Transport (DSLAMs, DSL Modems)

• Multicast Transmission over DSL and backbone (ATM and Gigabit Ethernet, IGMP-based)
• Scalability of DSLAMs:
  Number of simultaneous video channels        
  Number of multicast subscribers   
  Zapping Time under load
• Quality of service Prioritization, latency issues at DSLAM ATM traffic management, shaping xDSL single VC / multiple VC solutions

Video over DSL Service (Set-top boxes, content servers)

• End-to-end multicast transmission
• Video quality between encoder, network and decoder (set-top box)    
• Channel Provisioning at headend / content server
• Service Management Platform interoperability between Set-top boxes and headends (Program guide, set top box SW management)

 

We distinguished transport tests applicable to DSL modems and DSLAMs from service tests applicable to video headends and set-top boxes.

 

Service Tests

 

1. Video Quality: End-to-end quality of service

 

   To demonstrate the ability to maintain quality of service from the
   head-end to the modem through the backbone, showing interoperability
   with Ethernet or ATM based networks. (ITUT-T H.610 14.1.1 and 14.1.2)

 

   By generating traffic from both the backbone and the modem we verified
   that Quality of Service can be provided on the ADSL/SHDSL link
   between the modem and the DSLAM as well as in the backbone
   network all the way to the head-end.

 

2. Channel Provisioning: Video encapsulation at head-end

 

    To demonstrate the interoperability of head-end solutions to multiple
    Set-top boxes to display video streams. (ITU-T H.610 14.1)

 

    By having different types of head-end solutions and different types of
    set-top boxes connected to the same network we demonstrated
    video interoperability.

 

3. Service Management: Set-top to head-end interoperability

 

    To demonstrate the ability of each head-end solution to manage different
    set-top boxes.

 

    By connecting head-end solutions to set-top boxes from different vendors
    we showed interoperability of program guides, set-top software updates
    and channel control.

 

Transport Tests

1. Multicast Transmission over DSL

 

    To demonstrate the capability to transmit an IP multicast stream from the
    DSLAM to the modem, including the ability to use IGMPv2 for a
    channel switchover at the DSLAM.

 

    Using test equipment attached to both the DSLAM and one or more
    modems we distributed several IP multicast streams to a DSLAM,
    and verified correct subscription and forwarding activities at the DSL
    modems. We also initiated a channel switchover from the modem
    side to insure that the modem and the DSLAM process the IGMPv2
    packets correctly.

 

2. Multicast Transmission over the backbone (ATM and Ethernet/IP)

 

   To demonstrate the ability for a DSLAM to receive and forward multiple
   IP multicast streams in parallel. In the case of ATM, demonstrating the
   ability for DSM-CC to IGMP conversion and the ability for the CPE to
   send IGMPv2 messages to switch multicast streams.

 

3. Number of simultaneous IP multicast streams (video channels)

 

   To demonstrate the total number of Multicast streams a DSLAM can
   accept without frame loss.

 

4. Number of simultaneous IP multicast subscribers

   To verify that the DSLAM can replicate a Multicast stream to all ports

 

    Connecting as many modems to the DSLAM as possible, see if the
    DSLAM can forward one Multicast stream to all modems.

 

5. Zapping time under load

 

    To demonstrate the time taken for a CPE device to join/leave multicast
    streams while  the DSLAM is fully populated with incoming streams
    and subscribers.

 

6. Verify Quality of Service on the xDSL link using either a single virtual
    channel (VC) for all applications or multiple VCs for different
    applications