The OUDP leak detection feature is supported on the following line cards:

OUDP test sessions are created in the Exec CLI or Configuration mode and are maintained on the SUP and CLC line cards. A test session identifies a list of modems that will participate in the OUDP burst test, the frequency range to be tested, the transmit burst parameters, and the start and stop time of the test. Two types of OUDP test sessions are managed by the cBR-8, parent test sessions and child test sessions.

A parent test session is created on the SUP using Exec or Configuration CLI commands and is identified by a unique parent session Id. parent test sessions are set up to include the frequency range to be tested, the transmit burst parameters, and a cable modem mac-address list and/or an interface to be tested.

A child test session is created on the line card, has a child session Id that is unique to the slot and are associated with a parent test session. There can be 0, 1 or many child test sessions associated with a parent test session depending on the method used to identify the participating modem list. The child test sessions are set up with the minislot frequency range and transmit burst parameters corresponding to their parent test session. A unique child test session will be created for each OFDMA channel participating in the OUDP test.

All OUDP test sessions transition through a series of states as the test progresses.

The progression of an OUDP Test Session includes the following steps:

1. The Parent Test Session is fully set up on the SUP through the Exec CLI or Configuration commands.

2. At Pre-Test Setup time—a configurable time prior to the test start:

   Note	The default time is 1 minute.

   1. The parent test session is distributed to all cable line cards.

   2. The cable line cards determine whether they have any OFDMA channels that match the parent test parameters.

   3. The cable line cards create a unique child test session for each OFDMA channel with online D3.1 CMs based on the parent test parameters.

   4. The child test sessions are notified back to the SUP from the cable line card.

   5. Each participating CM is assigned a unique OUDP Test Session ID (SID).

   6. A DBC-REQ message is sent to each CM to set up its OUDP Test SID.

   7. The US Scheduler receives the test parameters for Burst Duration, Burst Gap, and Cycle Time.

   8. The US Scheduler receives the ordered list of SIDs to be scheduled for the OUDP test cycle.

3. At the start of the test, the US Scheduler begins granting on the OUDP Test SIDs.

4. Modems respond to the grants by transmitting the OUDP Test packets as defined in the MULPI specification. Modem bursts are periodic based on the configured OUDP test cycle and always occur at a fixed time-offset from the start of a test cycle.

5. Modem test bursts are received by the upstream PHY and processed by the upstream FPGA. The PHY and FPGA collect the stats for burst no energy, bursts received, and bytes received.

6. Stats collection for each SID occurs periodically, every 10 seconds, on the cable line card and are forwarded to the SUP.

7. The test continues until the test stop time is reached:

   1. Final Stats collection occurs for each CM.

   2. The US Scheduler SID list will be deleted.

   3. The US Scheduler OUDP minislot assignments will be cleared.

   4. Each modem will be sent the OUDP_DISABLE_SID to clear its OUDP Test SID.

   5. The OUDP test SIDs will be deallocated and deactivated and returned to the SID pool.

8. Test Session stats can be reviewed through CLI show commands.

9. Test Sessions are manually deleted or deleted automatically at the specified Expiry age.

An OUDP parent test session is a test session that is created on the SUP to run at a specific time, over a specific frequency range, using specific transmit burst parameters, and that includes a specific set of cable modems. When created using EXEC mode, the parent test session is not persistent. In other words, the Exec mode OUDP test session will be lost if the system is reloaded. To create a persistent OUDP test session the Configuration CLI mode should be used, and the configuration should be saved to startup-config.

A parent test session must include either a CM-List or an interface or both. The CM-List consists of a list of modem mac-addresses. The system supports a maximum of 400 mac-addresses in the CM-List. Mac-addresses included in the CM-List may be from a single slot/single OFDMA channel, or from several different slots on different OFDMA channels. Mac-addresses setup in the parent CM-List are not validated.

A parent test session may also include an interface. The interfaces supported include a mac-domain (for example Cable1/0/0), a controller (for example controller upstream-cable 1/0/4), or a controller channel (for example controller upstream-cable 1/0/4 us-channel 12). When both a CM-List and an interface are setup in a parent test session, the list of modems that will participate in the test will be the logical AND of the CM-List with the modems on the interface.

Multiple parent test sessions can be setup simultaneously. The cBR-8 will manage all parent test sessions appropriately based on their configured start and stop times. Parent test sessions are assigned Ids in the 1 – 9999 range. If a multiple parent test sessions exist that would otherwise include the same OFDMA channels and/or the same cable modems, the first parent test session to start will win. Subsequent overlapping parent test sessions will start on time, but will not include a child test session for an OFDMA channel that is already active in another parent test session.

Exec CLI commands are provided to manage parent test sessions. When commands like stop and delete are used on the parent test session, all related child test sessions will also be stopped and deleted.

When Exec CLIs are used to create a parent test session, the admin is allowed to choose the parent test session Id, which must be in the range 1-9999. When the cBR-8 restores persistent OUDP test sessions, it will create parent test sessions using the next available parent test session Id, starting from 1. Duplicate parent test session Ids are not allowed.

You can create a session by using the cable oudp-leak-detect session-id <id> session create command at the privileged EXEC mode. The specified ID is referred to as the parent ID.

The cBR-8 routers create child test sessions, automatically, as needed. The administrator cannot create the child test sessions directly. A child test session is created for each OFDMA channel that will be participating in an OUDP test. When the child test session is created, it is assigned a unique child session ID. Child session IDs are assigned a value that corresponds to the slot on which they originated.

For the child test session to be created, it must have at least one valid DOCSIS3.1 cable modem online and that modem must also be using the OFDMA channel.

Note	If the modem is reporting the OFDMA channel in partial service, it still joins and participates in the OUDP test. Grants will be issued to the modem, but as long as the modem reports partial-service on the OFDMA channel, it is possible that the BurstNoEnergyRx stat is incremented.

When a child test session is created from a parent test session, the frequency range of the parent test session is translated into a frequency range aligned with the OFDMA channel minislots that are inclusive of the parent frequency range. Thus, the child test session detailed information may show a minislot frequency range larger than the parent test session frequency range.

The child test session also inherits the transmit burst parameters of the parent test session. These values should always be identical to the parent.

Child test sessions also contain CM-List and interface configuration details. The interface of a child test session will always be a controller upstream-cable us-channel particular to a single OFDMA channel. The CM-List of a child session will only include the cable modems particular to the OFDMA associated with the child test session. By default, cable modems of a child test session are assigned burst positions within the OUDP test cycle starting from position 0. However, an option strict-cm-list exists that enforces the parent CM-List position on the child test sessions. For example, when the strict-cm-list option is used, a modem in CM-List position 5 of the parent CM-List appears in position 5 of the corresponding child test session CM-List.

Note	The strict-cm-list position should only be used if the exact time offset of the CM must be maintained within the OUDP test cycle. The use of this option can result in unused burst positions within the OUDP test.

Mac-addresses in the parent test session are validated as they are assigned to child test sessions. Mac-addresses in the CM-List that are invalid format, are not known on the system, are valid but the modem is offline, are not D3.1 cable modems, or are D3.1 cable modems that are not using an OFDMA channel will not participate in the OUDP test.

This show command output shows child sessions IDs and their associated parent ID:

Parent  Child       Interface   Modems  Status     Start-Time                    Stop-Time
    99      -          -        1        ACTIVE     2022-07-23,20:05:12.0,-5:00   never
    99  10006   Ca1/0/0/U6      1        ACTIVE     2022-07-23,20:05:12.0,-5:00   never
    99  10008  Ca1/0/2/U14      2        ACTIVE     2022-07-23,20:05:12.0,-5:00   never
    99  90007   Ca9/0/0/U6      2        ACTIVE     2022-07-23,20:05:12.0,-5:00   never
    99  90008   Ca9/0/1/U6      2        ACTIVE     2022-07-23,20:05:12.0,-5:00   never
    99  90009  Ca9/0/30/U6      1        ACTIVE     2022-07-23,20:05:12.0,-5:00   never
    99  90010  Ca9/0/31/U6      2        ACTIVE     2022-07-23,20:05:12.0,-5:00   never

OUDP test sessions set up using the Configuration CLI mode are persistent and known as scheduled OUDP test sessions. The parameters and options for configuration mode are similar to the commands offered by the Exec CLI, except for the cm-add or cm-delete Exec commands. In configuration mode, the CM-List is loaded from a file located on the hard drive, bootflash, or usb IOS file systems.

There are two types of scheduled OUDP test sessions.

• Date-Time

• Recurring Weekday

Date-Time schedules are configured to start and stop at a specified calendar date-and-time. The format follows the OSSI specification for Date-And-Time Strings:

[YY]YY-[M]M-[D]D,[h]h:mm:ss.0,[+|-][T]T:ZZ

Example: 2022-07-23,22:31:44.0,-5:00

In addition, Date-Time schedules support the option for start ‘now’ and stop ‘never’. These options are useful to reestablish OUDP test sessions automatically after a system reload.

Recurring Weekday schedules allow the administrator to create a scheduled OUDP test session that runs on specific days of the week, and during specific times of the day. The time-of-day is specified using 24-hour military time, and is relative to the local timezone of the cBR-8. Upon completion, a Recurring Weekday test will be rescheduled to start on the next subsequent weekday at the configured start time.

Persistent OUDP test sessions are configured by first creating an OUDP Burst Profile. The burst profile includes the test session parameters for frequency range, transmit burst parameters, interface and/or CM-List. Each OUDP burst profile is assigned a unique ID, and multiple burst profiles are supported.

After the burst profile is configured, a scheduled OUDP test session can be configured. The OUDP schedule binds the burst profile ID to the Date-Time or Recurring Weekday schedule. A single OUDP burst profile may be configured under one or more OUDP schedules. When the OUDP burst profile and schedule configurations are complete, an OUDP parent test session is created and associated with the OUDP schedule. The assigned parent test session ID can be shown using the show cable oudp-leak-detect schedules command.

CM-List Format

Configured OUDP test sessions may include a CM-List that is read from a file on harddisk, bootflash, or usb0 IOS file systems. The format rules for the file are as follows:

• File type is ASCII text.

• Enter one mac-address per line.

• Mac-addresses may be either aaaa.bbbb.cccc or aa:bb:cc:dd:ee:ff format.

• Blank lines are permitted.

• Comment lines are permitted and must start with # as the first character of the line.

• Comments or other characters should not follow MAC addresses.

• Include a <CR> after the final MAC address in the file.

Example

#
######  This is an example OUDP CM-List file.######

# C1/0/0
4800.33ef.00fa
4800.33ef.014a
4800.33ef.0142
4800.33ef.0b0e

# C1/0/2
1459.c0f8.5210
4800.33ef.0d6a
4800.33ee.ff9a
4800.33ea.70c2
4800.33ea.71ba

CM-List Wildcard

The CM-List supports a wildcard mac-address. The wildcard mac-address is ffff.ffff.ffff. When this mac-address is included in the CM-List (either Exec or Config created), it matches all eligible cable modems during child test session creation.

The wildcard CM-List is the easiest method for starting an OUDP test session on the entire cBR-8. All D3.1 modems using an OFDMA channel that matches the OUDP frequency range will be assigned to a child test session and will participate in the OUDP test session.

The cBR-8 provides a feature for D3.1 modems to join an OUDP test session after the test session has started. Cable modems that are offline at the start of a test, but otherwise intended to participate in the OUDP test session, are added to the OUDP test session after they register, provided:

1. The modem mac-address is included in the CM-List of the parent test session.

2. The parent test session includes the interface of the OFDMA channel that the modem is using.

A test session configured with only a CM-List:

• Allows late modem joining for modems whose mac-addresses are listed within the CM-List.

• Allows all eligible modems that contain the wildcard mac address ffff.ffff.ffff to join the test session.

A test session configured with only an interface will allow late modem joining only for new modems on the specified interface.

While an OUDP test session is active, the OUDP process will periodically check every 15 minutes to determine if new modems can be added to an existing test.

The cBR-8 router provides a feature for OUDP, where persistent OUDP test sessions will not be started until the system is up and the OFDMA channel reach UP state with cable modems online. The amount of time to wait after system boot-up is configurable. The persistent test sessions restored from startup-config will not be distributed to the cable line cards and child test sessions will not be created until the system-boot-holdoff time has elapsed.

Note	The default system-boot-holdoff time is 15 minutes.

The cBR-8 retains OUDP test sessions for a period of time after they have reached the COMPLETE state. This allows time for the administrator to retrieve CM burst statistics for post processing and analysis. However, OUDP test sessions occupy memory on both the SUP and cable line card processors, so they should be deleted in a timely fashion. To facilitate their deletion, the cBR-8 automatically deletes expired OUDP test sessions when they have aged beyond the globally configured expire-age. By default this is 3 days, and the value is configurable from 1 to 7 days.

The cBR-8 supports the high availability feature for OUDP leakage testing.

Supervisor High Availability (SUP-HA) is supported, with child test session CM burst stats restored to the newly active SUP shortly after switchover.

Line Card High Availability (LCHA) is also supported for OUDP leakage testing. After LCHA switchover, CM burst stats will continue to be collected and reported up to the SUP.

CM burst stats are reported periodically every 10 seconds, so it may take up to 20 seconds after switchover for stats to begin incrementing.

This example shows how to create a burst profile in the configuration mode:

Router#config terminal
Enter configuration commands, one per line.  End with CNTL/Z.
Router(config)#cable oudp-leak-detect burst-profile 55
Router(config-oudp-burst-profile)#frequency start 45000000 end 50000000
Router(config-oudp-burst-profile)#$burst duration 4 gap 2 cycle-gap 10
OUDP cycle-gap can support 53 bursts in the test cycle
Router(config-oudp-burst-profile)#cm-list harddisk:oudp-cm-list-1
Router(config-oudp-burst-profile)#$leak-detect schedule burst-profile 55 recurring 
   weekdays MoTuWeThFr start timeofday 15:45:00 stop timeofday 18:00:00

The example shows the creation of a session and assigning the required test parameters.

1. Configure an OUDP session.

   Router#cable oudp-leak-detect session-id 99 session create

2. Configure the frequency test parameters for the OUDP session.

   Router#cable oudp sess 99  frequency start 60000000 end 66000000

3. Configure the Burst Duration and Cycle Gap test parameters.

   Router#cable oudp sess 99  transmit burst duration 6 gap 4 cycle-gap 20
   OUDP cycle-gap can support 64 bursts in the test cycle

4. Configure the list of cable modems intended to participate in sending test bursts.

   Router#cable oudp sess 99 cm-add 4800.33ea.70c2
   Router#cable oudp sess 99 cm-add 4800.33ea.71ba
   Router#cable oudp sess 99 cm-add 4800.33ee.ff9a
   Router#cable oudp sess 99 cm-add 4800.33ef.0c56
   Router#cable oudp sess 99 cm-add 4800.33ef.0c5e

5. Configure the start time and end time for the test bursts.

   Router#cable oudp-leak-detect session-id 99 start datetime 2022-01-01,12:00:00.0,
     -5:00 stop datetime 2022-01-02,12:00:00.0,-5:00

The show cable oudp-leak-detect test-sessions command shows all OUDP test sessions present on the cBR-8. The status of each session will indicate whether it is PENDING with a future start time, in PRETEST_SETUP just prior to the test start, ACTIVE with OUDP burst grants, CLEANUP for final stats collection, or COMPLETE.

Router#show cable oudp-leak-detect test-sessions
Load for five secs: 5%/0%; one minute: 6%; five minutes: 6%
Time source is NTP, 14:14:05.873 EST Wed Jul 27 2022

OUDP Test Sessions: 2

Parent Child Interface    Modems  Status   Start-Time                  Stop-Time
99       -      -          0      ACTIVE     2022-07-27,12:45:03.0,-5:00 never
99      10002 Ca1/0/2/U14  2      ACTIVE     2022-07-27,12:45:03.0,-5:00 never

The show cable oudp-leak-detect session-id <id> detail command can be used for either parent or child test sessions. Parent session details show the test parameters as they are configured.

Router#show cable oudp-leak-detect session-id 99 detail
Load for five secs: 7%/0%; one minute: 6%; five minutes: 6%
Time source is NTP, 12:44:33.214 EST Wed Jul 27 2022

OUDP Test Session : 99 (parent)

Status : PRETEST
Start Time : 2022-07-27,12:45:03.0,-5:00
Stop Time : never
Burst Duration : 6 (frames)
Burst Gap : 4 (frames)
Cycle Gap : 20 (frames)
Reserved Probe Pct : 3
Freq Start : 60000000 (Hz)
Freq End : 66000000 (Hz)
Interface : controller upstream-cable 1/0/3 us-channel 12
CM-List : 0 modems

Child session detail shows test information as it pertains to the particular OFDMA channel.

Router#show cable oudp-leak-detect session-id 10002 detail
Load for five secs: 5%/0%; one minute: 6%; five minutes: 6%
Time source is NTP, 14:12:35.623 EST Wed Jul 27 2022

OUDP Test Session : 10002 (child)

Interface : Cable1/0/2 upstream 14
Status : ACTIVE
Start Time : 2022-07-27,12:45:03.0,-5:00
Stop Time : never
Burst Duration : 6 (frames)
Burst Gap : 4 (frames)
Cycle Gap : 20 (frames)
Reserved Probe Pct : 3

Actual SC Freq Start : 59700000 (Hz)
Actual SC Freq End : 66075000 (Hz)
Minislot Start : 38
Minislot End : 53
Microsec per frame : 573.000 (usec)
Burst Spacing : 5730.000 (usec)

Test Session Type : CycleGap
Current Bursts per cycle : 2
Maximum Bursts per cycle : 64
Probe Oppty per cycle : 20 (frames)
Cycle Interval Info : 2 (bursts) / 40.00 (frames) / 22.920 (msec)

Child Session 10002, Cable1/0/2 upstream 14 - CM-List 2 modems
CM Mac-Address BurstPos Offset(us)  Test Sid BurstGrants BurstNoEnergyRx BurstRx TestBytesRx
4800.33ea.71ba    0        0          27        1373428     0             1371040 2107288480
4800.33ea.70c2    1        5730       28        1373418     0             1371030 2107273110

This example is to create a test session where the operator has requested that the cBR-8 choose the modems.

MAC-Address Wildcard—All CLCs and All OFDMA channels

cable oudp-leak-detect session-id 5 session create
cable oudp-leak-detect session-id 5 frequency start 138100000 end 139650000
cable oudp-leak-detect session-id 5 transmit burst duration 4 gap 2 cycle-gap 10
cable oudp-leak-detect session-id 5 cm-add FFFF.FFFF.FFFF
cable oudp-leak-detect session-id 5 start datetime 2022-01-01,12:00:00.0,-5:00
stop datetime 2022-01-02,12:00:00.0,-5:00 

MAC-Domain Example—All configured OFDMA channels on the MAC-Domain

cable oudp-leak-detect session-id 5 interface Cable9/0/0

Controller Example—Single controller and one or two OFDMA channels

cable oudp-leak-detect session-id 5 controller upstream-cable 9/0/0 
cable oudp-leak-detect session-id 5 controller upstream-cable 9/0/0 us-channel 13

The support for RF leakage detection is defined in the following specifications:

• CableLabs OSSI Specification: CM-SP-CCAP-OSSIv3.1-I24-220518

  Note	The implementation tracks closely to, but does not 100% match the OSSI specification. OSSI specification development was in progress during the time of this implementation.

• Upstream OFDMA Data Profile Testing Burst method as defined in the CableLabs MULPI Specification CM-SP-MULPIv3.1-I23-220328

• OFDMA channel IUC 13 is used by the the cBR-8 to schedule test bursts. Change the IUC 13 parameters as necessary to match compatibility with the leakage detection equipment in use.

• Operations Support System Interface (OSSI) recommends the use of pilot pattern 4 or 11 for OFDMA Burst Testing. OSSI recommends not to use boosted pilot patterns.

• cBR-8 supports all OFDMA pilot pattern configurations for OFDMA Burst Testing, if desired by the operator.

This example shows the channel configuration for detecting leaks using a digital leak detector.

The following steps are to configure OFMDA controller profile:

Router# enable
Router# configure terminal
Router(config)#cable mod-profile-ofdma 420
Router(config)#subcarrier-spacing 25KHz
Router(config)#initial-rng-subcarrier 64
Router(config)#initial-rng-preamble 8
Router(config)#fine-rng-subcarrier 512
Router(config)#data-iuc 9 modulation 2048-QAM pilot-pattern 9
Router(config)#data-iuc 10 modulation 1024-QAM pilot-pattern 9
Router(config)#data-iuc 11 modulation 512-QAM pilot-pattern 8
Router(config)#data-iuc 12 modulation 256-QAM pilot-pattern 8
###### CableLabs OSSI recommends 11 for 25 kHz SC spacing######
######CableLabs OSSI recommends 4 for 50 kHz SC spacing######
###### CableLabs OSSI recommends not to use boosted pilot patterns######
Router(config)#data-iuc 13 modulation 64-QAM pilot-pattern 11######

To configure upstream controller profile, use the steps below:

Router# enable
Router# configure terminal
Router(config)#cable upstream controller-profile id [RPHY|I-CMTS]
Router(config)#us-channel 13 docsis-mode ofdma
Router(config)#us-channel 13 subcarrier-spacing 25KHz
Router(config)#us-channel 13 modulation-profile 420
Router(config)#us-channel 13 frequency-range 108000000 204000000
Router(config)#us-channel 13 initial-rng-frequency-start 184000000
Router(config)# us-channel 13 cyclic-prefix 256 roll-off-period 128
Router(config)#us-channel 13 symbols-per-frame 9
Router(config)#no us-channel 13 shutdown