Table of Contents
Cisco uBR7246 Universal Broadband Router Feature EnhancementsFeature Summary
Benefits
List of Terms
Supported Platforms
Prerequisites
Supported MIBs and RFCs
Configuration Tasks
Configuring Spectrum Groups
Configuring Frequency Hopping
Verify
Configuration Examples
Command Reference
cable downstream modulation
cable downstream rate-limit
cable flap-list aging
cable flap-list insertion-time
cable flap-list power-adjust threshold
cable flap-list size
cable helper-address
cable insertion-interval
cable match address
cable modulation-profile
cable privacy
cable qos permission
cable qos profile
cable relay-agent-option
cable shared-secret
cable spectrum-group band
cable spectrum-group frequency
cable spectrum-group hop period
cable spectrum-group hop threshold
cable spectrum-group shared
cable upstream admission-control
cable upstream channel-width
cable upstream data-backoff
cable upstream minislot-size
cable upstream modulation-profile
cable upstream range-backoff
cable upstream rate-limit
clear cable flap-list
clear cable modem counters
clear cable modem reset
ping cable-modem
show cable flap-list
show cable modem
show cable modulation-profile
show cable qos permission
show cable qos profile
show cable spectrum-group
show controllers cable
show interface cable
show interface cable sid
show interface cable signal-quality
test cable atp cable
Debug Commands
debug cable mac
debug cable map
What to Do Next
Cisco uBR7246 Universal Broadband Router Feature Enhancements
Feature Summary
The enhancements to the Cisco uBR7246 cable router extend and improve the command line interface (CLI). It supports burst profile, quality of service (QoS), improved parameter configuration, the MC11 modem card, and the MC16 modem card.
Downstream QoS handling is compliant with Multimedia Cable Network System (MCNS) requirements, and upstream QoS handling and Spectrum Management have been improved.
The Cisco uBR7246 now supports multicast authentication via RADIUS, and security has been enhanced for baseline privacy (including MCNS Data Over Cable System Interface Specification (DOCSIS) compliance). Also, this cable router now supports Dynamic Host Configuration Protocol (DHCP) Relay Subscriber ID Insertion.
Benefits
These enhancements to the Cisco uBR7246 cable router bring value to the digital broadband network by:
List of Terms
AmplifierUsed on coaxial segments of a Community Antenna Television (CATV) plant to restore signal levels lost due to attenuation through distance. Unfortunately, amplifiers amplify noise as well as signal.
Branch LineA coaxial cable that runs from a trunk line to a subscriber drop point. A branch line is also known as "Feeder Cable."
Cable ModemAny device which modulates and demodulates digital data onto a CATV plant.
Cable Line CardModem front-end card of the cable router headend unit, plugged into the midplane. Each Cable Line Card provides a number of radio frequency (RF) channels as external interfaces.
Cable RouterA modular chassis-based router optimized for the data over CATV hybrid fiber-coaxial (HFC) application.
CATVOriginally Community Antenna Television. Now used to refer to any cable-based (coaxial/fiber) system provision of television services.
CDMTS, CMTSCable (Data) Modem Termination System.
ChannelA specific frequency allocation and bandwidth. Downstream channels used for television in the US are 6 MHz wide. In Europe, downstream channel width is 8 MHz.
Combiner GroupThe return paths of several fiber nodes can be combined at a single point to form one RF domain. This single point is called a combiner group. See also Spectrum Group.
CPECustomer Premises Equipment. In the Cable Router application, this will usually be one or multiple PCs located at the customer side.
Distribution HubA smaller or remote headend distribution point for a CATV system. Video signals are received here from another site (headend), and redistributed. Sometimes a small number of locally originated signals are added. Such signals might be city information channels, HFC cable modem signals, and so forth.
DownstreamThe set of frequencies used to send data from a headend to a subscriber.
DropA subscriber access point. The actual coaxial connection in the subscribers home.
Fiber Node, NodeAn optical node located in the outside plant distribution system which terminates the fiber-based downstream signal as an electrical signal onto a coaxial RF cable. Each fiber node is defined to support a certain serving area, either defined by number of homes passes or total amplifier cascade (number of active amplifiers in the longest line from the node to the end of the line).
HeadendCentral distribution point for a CATV system. Video signals are received here from satellite (either co-located or remote), the frequency is converted to the appropriate channels, combined with locally originated signals, and rebroadcast onto the HFC plant. For a CATV data system, the headend is the typical place to link between the HFC system and any external data networks.
HFCHybrid fiber-coaxial. Older CATV systems were provisioned using only coaxial cable. Modern systems use fiber transport from the headend to an optical node located in the neighborhood to reduce system noise. Coaxial cable runs from the node to the subscriber. The fiber plant is generally a star configuration with all optical node fibers terminating at a headend. The coaxial cable part of the system is generally a trunk and branch configuration.
Homes PassedThe number of homes or offices potentially serviceable by a cable system either on a per node or per system basis.
MidsplitA frequency allocation plan where 5 to 108 MHz is used for upstream data and 178+ MHz is used for downstream data.
Optical NodeA device used to convert broadband RF (for example, television signals) to/from a fiber optic signal. An optical node is typically located in the outside field.
PredatorCode name for the Cisco 7200 class of modular routers that accept PCI bus-based port adapters.
QAMModulation scheme mostly used in the downstream direction (QAM-64, QAM-256). QAM-16 is expected to be usable in the upstream direction. Numbers indicate number of code points per symbol. Number of bits per symbol can be computed by 2(number of bits/symbol) = number of code points.
QPSKModulation scheme used in the upstream direction. Supports two data bits per symbol.
Spectrum GroupA combiner group can be associated with a frequency hop table. This frequency hop table associated with a combiner group is the spectrum group, as opposed to the RF topology point, which is the combiner group. See also Combiner Group.
SubsplitA frequency allocation plan where 0 to 42 MHz is used for upstream data and 50+ MHz is used for downstream data.
TapA passive device that divides the signal between the trunk or feeder lines and splits the signal into ports for subscriber drop access.
Telephony ReturnA variant of a cable data system where the return path from the subscriber cable modem is routed over a dialup (or ISDN) connection instead of over an upstream channel.
Trunk LineA CATV backbone coaxial cable. This runs from an Optical Node and through a specific neighborhood or serving area.
UpstreamThe set of frequencies used to send data from a subscriber to the headend.
Supported Platforms
This feature is supported on the Cisco uBR7246 router only.
Prerequisites
Complete the basic configuration of the Cisco uBR7246 as described in the Cisco uBR7246 Universal Broadband Router Installation and Configuration Guide and the Voice, Video, and Home Applications Configuration Guide.
Supported MIBs and RFCs
The Cisco uBR7246 feature enhancements support the Radio Frequency (RF) Interface Management Information Base (MIB). For descriptions of supported MIBs and how to use MIBs, see Cisco's MIB website on Cisco Connection Online (CCO) at the following URL: http://www.cisco.com/public/sw-center/netmgmt/cmtk/mibs.shtml.
No RFCs are supported by this feature.
Configuration Tasks
The basic configuration tasks required by this version of the Cisco uBR7246 cable router are the same as those described in the Cisco uBR7246 Universal Broadband Router Installation and Configuration Guide and the Voice, Video, and Home Applications Configuration Guide.
Additional configuration tasks are:
- Configuring Spectrum Groups (Optional)
- Configuring Frequency Hopping (Optional)
Configuring Spectrum Groups
You can configure upstream frequency hop tables using cable spectrum-group commands. Start by determining which upstream ports are assigned to a combiner group. Then apply the following steps to configure a spectrum group:
| Step | Command | Purpose |
|---|---|---|
| 1 |
Create the frequency hop table under Cisco IOS global configuration mode. |
|
| 2 |
Assign the upstream port to the frequency hop table under Cisco IOS interface configuration mode. |
Configuring Frequency Hopping
To configure frequency hopping, apply the following steps:
After you have established basic operation, inject a tone to the upstream port. For example, if the upstream frequency is currently 22.4 MHz, inject a 22.4 MHz tone at approximately the same power level as the modem. (If the power level at the modem is 40 dBmV, set the tone power to 40 dBmV.) The interfering carrier should kill the channel and cause the frequency to change to the next configured value. In this example, it would be 24.0 MHz.
If you do not have an RF tone generator, use another line card and modem carrying traffic. Connect the upstream to the same combiner group and use the data carrier as an interfering signal by setting it to the same frequency. For example, to test frequency hopping on c3/0, install c4/0 and connect both upstreams together using a combiner. If the upstream frequency of c3/0 is currently 22.4 Mhz, then set c4/0 to 22.4 Mhz while c4/0 is carrying traffic. This should force c3/0 to change the frequency to the next configured value.
Verify
The verification tasks required by this version of the Cisco uBR7246 cable router are the same as those described in the Cisco uBR7246 Universal Broadband Router Installation and Configuration Guide and the Voice, Video, and Home Applications Configuration Guide.
Configuration Examples
To illustrate configuring spectrum groups, assume that an MC16 card is in slot 3 and is named Cable3/0. Its upstream ports are named U0 through U5. You want ports U0 through U3 to belong to one combiner group, and ports U4 and U5 to belong to a different combiner group because of higher subscriber penetration. In both combiner groups, the allocated spectrum should be three 3.2 MHz slots centered at 21.6, 24.8, and 28.0 MHz. The allocated spectrum is 20.0 to 29.6 MHz. From global configuration mode, enter the configure terminal command. Then enter:
Spectrum group 1 will be used for ports U0 through U3. Spectrum group 2 will be used for ports U4 and U5. Because ports U4 and U5 belong to the same combiner group, spectrum group 2 is configured as shared. The shared keyword prevents frequency collision.
To assign the upstream ports to the frequency hop tables for slot 3, enter:
The upstream ports are assigned frequencies from their respective spectrum groups. Ports U0 through U3 will be set to 21.6 MHz. Ports U4 and U5 will be set to 21.6 and 24.8 MHz, respectively.
For additional configuration examples, refer to the Cisco uBR7246 Universal Broadband Router Installation and Configuration Guide and the Voice, Video, and Home Applications Configuration Guide.
Command Reference
This section documents new or modified commands. All other commands used with this feature are documented in the Cisco IOS Release 11.3 command references.
- cable downstream modulation
- cable downstream rate-limit
- cable flap-list aging
- cable flap-list insertion-time
- cable flap-list power-adjust threshold
- cable flap-list size
- cable helper-address
- cable insertion-interval
- cable match address
- cable modulation-profile
- cable privacy
- cable qos permission
- cable qos profile
- cable relay-agent-option
- cable shared-secret
- cable spectrum-group band
- cable spectrum-group frequency
- cable spectrum-group hop period
- cable spectrum-group hop threshold
- cable spectrum-group shared
- cable upstream admission-control
- cable upstream channel-width
- cable upstream data-backoff
- cable upstream minislot-size
- cable upstream modulation-profile
- cable upstream range-backoff
- cable upstream rate-limit
- clear cable flap-list
- clear cable modem counters
- clear cable modem reset
- ping cable-modem
- show cable flap-list
- show cable modem
- show cable modulation-profile
- show cable qos permission
- show cable qos profile
- show cable spectrum-group
- show controllers cable
- show interface cable
- show interface cable sid
- show interface cable signal-quality
- test cable atp cable
cable downstream modulation
To set the modulation rate for a downstream port on a cable modem card, use the cable downstream modulation cable interface configuration command:
- cable downstream modulation {64qam | 256qam}
Syntax Description
Default
Command Mode
Usage Guidelines
This command first appeared in Cisco IOS Release 11.3 XA.
Downstream modulation defines the modulation type used for downstream traffic. Specifying the symbol rate indirectly influences the interface speed; at 64qam, the interface speed is 6xx bits/second. Specifying 256qam sets the interface speed to 8xx bits/second.
Example
The following example sets the downstream modulation:
cable downstream rate-limit
To enable Data Over Cable Services Interface Specification (DOCSIS) rate limiting on downstream traffic, use the cable downstream rate-limit interface configuration command. Use the no form of this command to disable DOCSIS rate-limiting on downstream traffic.
- cable downstream rate-limit [token-bucket | weighted-discard] [exp-weight]
no cable downstream rate-limit
Syntax Description
|
(Optional) Specifies the weight for the exponential moving average of loss rate. Valid values are from 1 to 4. |
Default
cable downstream rate-limit, which enforces strict DOCSIS-complaint rate limiting.
Command Mode
Usage Guidelines
This command first appeared in Cisco IOS Release 11.3(6)NA.When you enter this command without an option, it enables strict DOCSIS-compliant rate limiting, which sets the burst rate to the interface speed.
Example
The following example applies the token bucket filter algorithm:
Related Commands
cable flap-list aging
To specify the number of days to age the cable modem from the flap-list table, use the cable flap-list aging global configuration command. Use the no form of this command to disable this feature.
- cable flap-list aging number of days
no cable flap-list aging
Syntax Description
|
Specifies how many days of cable modem performance is retained in the flap list. Valid values are from 1 to 60 days. |
Default
Command Mode
Usage Guidelines
This command first appeared in Cisco IOS Release 11.3 NA.
A flap list is a table maintained by the Cisco uBR7246 for every modem (active or not) that is having communication difficulties. (Flapping refers to the rapid disconnecting and reconnecting of a cable modem that is having problems holding a connection.) The flap list contains modem MAC addresses and logs the time of the most recent activity. You can configure the size and entry thresholds for the flap list.
Example
The following example specifies that the flap-list table retain two days of performance for this cable modem:
Related Commands
cable flap-list insertion time
cable flap-list size
cable flap-list power-adjust threshold
cable flap-list miss-threshold
clear cable flap-list
cable flap-list insertion-time
To set the insertion time interval, use the cable flap-list insertion-time global configuration command. Use the no form of this command to disable insertion time.
- cable flap-list insertion-time seconds
no cable flap-list insertion-time
Syntax Description
|
Insertion time interval in seconds. Valid values are from 60 to 86400 seconds. |
Default
Command Mode
Usage Guidelines
This command first appeared in Cisco IOS Release 11.3 NA. This command controls the operation of a flapping modem detector. When the link establishment rate of a modem is shorter than the period defined by this command, the modem is placed in the flap list.
Example
The following example sets the insertion time interval to 62 seconds:
Related Commands
cable flap-list size
cable flap-list power-adjust threshold
cable flap-list aging
cable flap-list miss-threshold
clear cable flap-list
cable flap-list power-adjust threshold
To specify the power-adjust threshold for recording a flap-list event, use the cable flap-list power-adjust threshold global configuration command. Use the no form of this command to disable power-adjust thresholds.
- cable flap-list power-adjust threshold dBmV
no cable flap-list power-adjust threshold
Syntax Description
Default
Command Mode
Usage Guidelines
This command first appeared in Cisco IOS Release 11.3 NA. This command controls the operation of a flapping modem detector. When the power adjustment of a modem exceeds the threshold, the modem is placed in the flap list.
Example
The following example the following command sets the power-adjust threshold to 1:
Related Commands
cable flap-list insertion time
cable flap-list size
cable flap-list aging
cable flap-list miss-threshold
clear cable flap-list
cable flap-list size
To specify the maximum number of modems reported in the flap-list table, use the cable flap-list size global configuration command. Use the no form of this command to specify the default flap-list table size.
- cable flap-list size number
no cable flap-list size
Syntax Description
|
Specifies the number of modems that report flap performance to the flap-list table. Valid values are from 1 to 8191. |
Default
Command Mode
Usage Guidelines
This command first appeared in Cisco IOS Release 11.3 NA.
Example
The following example limits the flap-list table size to no more than 2 modems:
Related Commands
cable flap-list size
cable flap-list power-adjust threshold
cable flap-list aging
cable flap-list miss-threshold
clear cable flap-list
cable helper-address
To specify a destination address for User Datagram Protocol (UDP) broadcast (DHCP) packets, use the cable helper-address interface configuration command. Use the no form of this command to disable this feature.
- cable helper-address IP-address {cable-modem | host}
no cable helper-address IP-address {cable-modem | host}
Syntax Description
|
Specifies that only cable modem UDP broadcasts are forwarded. |
|
Default
Command Mode
Usage Guidelines
This command first appeared in Cisco IOS Release 11.3 NA. If you specify a secondary interface address, the giaddr field in the DHCP requests will be sent to the primary address for DHCP requests received from cable modems, and to the secondary IP address for DHCP requests received from hosts.
Examples
The following example forwards UDP broadcasts from cable modems to the DHCP server at 172.23.66.44:
The following example forwards UDP broadcasts from hosts to the DHCP server at 172.23.66.44:
cable insertion-interval
To set the time between opportunities for cable modems to request a connection from the Cisco uBR7246, use the cable insertion-interval interface configuration command. Use the no form of this command to use the automatic setting and ignore any minimum or maximum time settings.
- cable insertion-interval [automatic] [min | max]
no cable insertion-interval
Syntax Description
Default
automatic (dynamically varying the frequency of initial ranging upstream slots between 50 milliseconds to 2 seconds).
Command Mode
Usage Guidelines
This command first appeared in Cisco IOS Release 11.3 NA. Use this command to configure the frequency at which the initial maintenance interval is to appear in MAP messages. MAP messages define the precise time intervals during which modems can transmit.
Use the automatic keyword with this command when you have to bring a lot of modems on line quickly (for example, after a major power failure). Override the automatic keyword by specifying an insertion interval.
Example
The following example specifies the automatic setting:
Related Commands
cable match address
To specify that IP multicast streams be encrypted, use the cable match address interface configuration command. Use the no form of this command if you do not want to use encryption.
- cable match address access-list
no cable match address
Syntax Description
|
Specifies that the IP multicast streams defined by the access list be encrypted. Access lists can be IP access list numbers or an IP access list name. Valid access list numbers are from 100 to 199. |
Default
Command Mode
Usage Guidelines
This command first appeared in Cisco IOS Release 11.3 NA. Configure the access list using the ip access-list command.
Examples
The following example specifies that the multicast stream defined by the access list named reno be encrypted:
The following example specifies that the multicast stream defined by the access list number 102 be encrypted:
Related Commands
cable modulation-profile
To define the modulation profile, use the cable modulation-profile global configuration command. Use the no form of this command to remove the specified modulation profile.
- cable modulation-profile profile iuc fec-tbytes fec-len burst-len guard-t mod scrambler seed diff pre-len last-cw uw-len
no cable modulation-profile profile iuc fec-tbytes fec-len burst-len guard-t mod scrambler seed diff pre-len last-cw uw-len
Syntax Description
Default
Command Mode
Usage Guidelines
This command first appeared in Cisco IOS Release 11.3 NA.
You can use the no form of this command to remove all modulation profiles except modulation profile 1. In the case of modulation profile 1, the no form of this command sets all of the parameters in a burst to default values.
Changes to modulation profiles causes changes to the physical layer. Because changing physical layer characteristics affects router performance and function, this task should be reserved for expert users.
Example
The following example defines the burst parameters for profile 2 as follows:
The request burst is defined to have 0 fec-tbytes, 16 kbytes fec-len, a burst-len of 1, a guard time of 8, a mod value of qpsk, scrambler enabled with a seed value of 152, differential encoding disabled, a preamble length of 64 bits, a fixed code word length, and 8-bit unique words for upstream unique word length. The remaining initial, station, short, and long bursts are defined in similar fashion for profile 2.
Note You have to create all of the bursts (request, initial, station, short and long) for this modulation profile to use the modulation profile command.
See Table 5 for a description of the output display fields.
Related Commands
cable upstream modulation-profile
show cable modulation-profile
cable privacy
To enable privacy in the system, use the cable privacy interface configuration command. Use the no form of this command to disable privacy.
- cable privacy [mandatory | authenticate-modem | authorize-multicast]
no cable privacy
Syntax Description
|
(Optional) Use AAA protocols to authenticate all modems during BPI initialization. |
|
|
(Optional) Use AAA protocols to authorize all multicast stream (IGMP) join requests. |
Default
Command Mode
Usage Guidelines
This command first appeared in Cisco IOS Release 11.3 NA. While the default for this command is to enable privacy, it is not mandatory.
Examples
The following example displays the options available with this command:
The following example forces Baseline Privacy to be used for all modems:
The following example turns on BPI modem authentication:
The following example turns on BPI muticast authorization:
Related Commands
cable qos permission
To specify permission for updating the QoS table, use the cable qos permission global configuration command. Use the no form of this command to remove a previously enabled permission.
- cable qos permission {create-snmp | modems | update-snmp}
no cable qos permission
Syntax Description
|
Permits creation of QoS table entries by Simple Network Management Protocol (SNMP). |
|
|
Permits creation of QoS table entries by modem registration requests. |
|
Default
Command Mode
Usage Guidelines
This command first appeared in Cisco IOS Release 11.3 NA.
Example
The following example enables modems to request arbitrary QoS parameters:
Related Commands
cable qos profile
show cable qos permission
show cable qos profile
cable qos profile
To configure a QoS profile, use the cable qos profile global configuration command. Use the no form of this command to either set default values for profile group numbers 1 or 2, or remove the QoS profile if no specific parameters remain.
- cable qos profile {groupnum | guaranteed-upstream | max-burst | max-upstream | max-downstream | priority | tos-overwrite | value}
no cable qos profile {groupnum | guaranteed-upstream | max-burst | max-downstream | priority | tos-overwrite | value}
Syntax Description
Default
Command Mode
Usage Guidelines
This command first appeared in Cisco IOS Release 11.3 NA.
Examples
The following examples configure QoS profile 4 with guaranteed upstream of 2 kbps, maximum transmission burst of 2, maximum downstream rate of 3 kbps, with a priority of 4, cable baseline privacy set, and a tos-overwrite mask and value byte (in hex) of 0x2:
Related Commands
cable qos permission
show cable qos profile
cable relay-agent-option
To enable the system to insert the cable modem MAC address into a DHCP packet received from a modem or host and forward the packet to a DHCP server, use the cable relay-agent-option interface configuration command. Use the no form of this command to disable insertion.
- cable relay-agent-option
no cable relay-agent-option
Syntax Description
This command has no keywords or arguments.
Default
Command Mode
Usage Guidelines
This command first appeared in Cisco IOS Release 11.3 NA. This functionality enables a DHCP server to identify the user (cable modem) sending the request and initiate appropriate action based on this information.
Example
The following example enables the insertion of DHCP relay agent information into DHCP packets:
cable shared-secret
To configure authentication and data privacy parameters, use the cable shared-secret interface configuration command. Use the no form of this command to disable authentication during the modem's registration phase.
- cable shared-secret [0 | 7] authentication-key
no cable shared-secret
Syntax Description
Default
Command Mode
Usage Guidelines
This command first appeared in Cisco IOS Release 11.3 XA.
Example
The following example activates cable modem authentication, using "3344912349988...sf" as the shared secret key and indicating that an encrypted message follows:
cable spectrum-group band
To configure a continuous band setting for a spectrum group, use the cable spectrum-group band global configuration command. Use the no form of this command to delete the band settings for a spectrum group.
- cable spectrum-group group-number [time day hh:mm:ss] [delete] band start-freq-hz end-freq-hz [power-level-dbmv]
no cable spectrum-group group-number
Syntax Description
Default
Command Mode
Usage Guidelines
This command first appeared in Cisco IOS Release 11.3 XA1. This command specifies that a continuous band setting be used as a unit of allocated spectrum within this spectrum group. Cable plants can choose to set up a daily schedule that changes the input power level and not the frequency.
Examples
The following example specifies that all the upstream ports for spectrum-group 4 share the same spectrum from 5000004 Hz to 40000000 Hz with a power level of 5 dBmV on Mondays at noon:
The following example deletes the frequency band created in the previous example:
cable spectrum-group frequency
To configure a spectrum group to use a center frequency, use the cable spectrum-group frequency global configuration command. Use the no form of this command to delete the configured frequency setting for this spectrum group.
- cable spectrum-group groupnum [time day hh:mm:ss] [delete] frequency freq-hz [dBmV]
no cable spectrum-group groupnum [time day hh:mm:ss] [delete] frequency freq-hz [dBmV]
Syntax Description
Default
Command Mode
Usage Guidelines
This command first appeared in Cisco IOS Release 11.3 XA1. A spectrum group allows the upstream frequency and input power level to change whenever noise impairs upstream traffic.
Cable plants can choose to set up a daily schedule that changes the input power level and not the frequency.
Example
The following example configures spectrum group 4 with an upstream frequency of 5000004 Hz and a power level of 5 dBmV:
cable spectrum-group hop period
To set the frequency-hop period, use the cable spectrum-group hop period global configuration command. Use the no form of this command to delete the frequency hop period for this spectrum group.
- cable spectrum-group groupnum hop period seconds
no cable spectrum-group groupnum hop period
Syntax Description
|
Specifies the frequency-hop time period in seconds. Valid values are from 1 to 3600. |
Default
Command Mode
Usage Guidelines
This command first appeared in Cisco IOS Release 11.3 NA.
Example
The following example sets the frequency-hop period to 60 seconds:
Related Commands
cable spectrum-group hop threshold
cable spectrum-group hop threshold
To specify a hop threshold for a spectrum group, use the cable spectrum-group hop threshold global configuration command. Use the no form of this command to delete the hop threshold for this spectrum group.
- cable spectrum-group groupnum hop threshold [percent]
no cable spectrum-group groupnum hop threshold
Syntax Description
|
(Optional) Specifies the hop threshold. Valid range of modems used is 1 to 100%. |
Default
Command Mode
Usage Guidelines
This command first appeared in Cisco IOS Release 11.3 NA.
Example
The following example sets the threshold which triggers frequency hop to 20% for spectrum-group 4:
Related Commands
cable spectrum-group hop period
cable spectrum-group shared
To specify that the upstream ports share the same spectrum, use the cable spectrum-group shared global configuration command. Use the no form of this command to delete the spectrum group.
- cable spectrum-group groupnum shared
no cable spectrum-group groupnum shared
Syntax Description
Default
Upstream port frequency same for all ports in the spectrum group.
Command Mode
Usage Guidelines
This command first appeared in Cisco IOS Release 11.3 NA. Because this command forces upstream ports to use the same spectrum, do not use this command for overlapping carriers.
Example
The following example specifies that all the upstream ports for spectrum-group 4 share the same spectrum:
cable upstream admission-control
To specify the percentage overbooking rate, use the cable upstream admission-control interface configuration command. Use the no form of this command to disable upstream admission control.
- cable upstream portnum admission-control percentage
no cable upstream portnum admission-control
Syntax Description
|
Specifies the percentage overbooking rate to limit overbooking. Valid values are from 100 to 10000 percent. |
Default
Command Mode
Usage Guidelines
This command first appeared in Cisco IOS Release 11.3(6)NA.
Example
The following example limits overbooking on upstream port 4 to 1000%:
cable upstream channel-width
To specify an upstream channel width, use the cable upstream channel-width interface configuration command. Use the no form of this command to set the channel width to 1600000 for a port number.
- cable upstream portnum channel-width width
no cable upstream portnum channel-width
Syntax Description
Default
Command Mode
Usage Guidelines
This command first appeared in Cisco IOS Release 11.3 NA.
Example
The following example configures port 2 with a channel width of 200,000 Hz (which is equivalent to a symbol rate of 160 ksym/s):
cable upstream data-backoff
To specify automatic or fixed start and stop values for data backoff, use the cable upstream data-backoff interface configuration command. Use the no form of this command to use the default data backoff values.
- cable upstream portnum data-backoff {automatic | start end}
no cable upstream portnum data-backoff
Syntax Description
Default
Command Mode
Usage Guidelines
This command first appeared in Cisco IOS Release 11.3 NA. Cisco recommends that you use this automatic setting.
Example
The following example sets the automatic values for port 2:
cable upstream minislot-size
To specify a minislot size, use the cable upstream minislot-size interface configuration command. Use the no form of this command to set the default minislot size of 8 if this is valid for the current channel width setting.
- cable upstream portnum minislot-size size
no cable upstream portnum minislot-size
Syntax Description
Default
Command Mode
Usage Guidelines
This command first appeared in Cisco IOS Release 11.3(6)NA.
Using values of 64 or 128 for higher symbol rates such as 1280 Ksymb/sec or 2560 Ksymb/sec can cause performance problems. Depending on your current setting's symbol rate, you should select the minislot size (in ticks) that yields a minislot size of 32 or 64 symbols.
Example
The following example sets the minislot size on upstream port 4 to 16 (or 256 symbols):
cable upstream modulation-profile
To assign a modulation profile to an interface, use the cable upstream modulation-profile interface configuration command. Use the no form of this command to assign modulation profile 1 to the interface.
- cable upstream portnum modulation-profile profile
no cable upstream portnum modulation-profile
Syntax Description
Default
Command Mode
Usage Guidelines
This command first appeared in Cisco IOS Release 11.3 NA.
Example
The following example assigns modulation profile 8 to port (interface) 2:
Related Commands
cable upstream range-backoff
To specify automatic or configured initial ranging backoff calculation, use the cable upstream range-backoff interface configuration command. Use the no form of this command to set default values.
- cable upstream portnum range-backoff {automatic | start end}
no cable upstream portnum range-backoff
Syntax Description
|
Binary exponential algorithm. Sets the start value for data backoff. Valid values are from 0 to 15. |
|
|
Binary exponential algorithm. Sets the end value for data backoff. Valid values are from 0 to 15. |
Default
Command Mode
Usage Guidelines
This command first appeared in Cisco IOS Release 11.3 NA.
Example
The following example sets the range backoff to automatic for port 2:
cable upstream rate-limit
To set DOCSIS rate limiting for an upstream port on a cable modem card, use the cable upstream rate-limit interface configuration command. Use the no form of this command to disable DOCSIS rate limiting for an upstream port on a cable modem card.
- cable upstream portnum rate-limit [token-bucket]
no cable upstream portnum rate-limit
Syntax Description
Default
Rate limit of the cable upstream port.
Command Mode
Usage Guidelines
This command first appeared in Cisco IOS Release 11.3(6)NA.
Use of the default value (the upstream port's rate limit) enforces strict DOCSIS-compliant rate limiting.
Example
The following example uses the token bucket filter algorithm for upstream port 4:
Related Commands
clear cable flap-list
To reset the flap-list table, use the clear cable flap-list privileged EXEC configuration command:
- clear cable flap-list [mac-addr | all]
Syntax Description
|
(Optional) MAC address. Specify the 48-bit hardware address of an individual cable modem. |
|
Default
Command Mode
Usage Guidelines
This command first appeared in Cisco IOS Release 11.3 NA.
Example
The following example removes all the modems from the flap-list table:
Related Commands
cable flap-list aging
cable flap-list insertion time
cable flap-list size
cable flap-list power-adjust threshold
cable flap-list miss-threshold
clear cable modem counters
To reset a cable modem's flapping counters to zero, use the clear cable modem counters privileged EXEC configuration command:
- clear cable modem {mac-addr | ip-addr | all} counters
Syntax Description
|
MAC address. Specify the 48-bit hardware address of an individual cable modem. |
|
|
IP address. Specify the IP address of an individual cable modem. |
|
Default
Command Mode
Usage Guidelines
This command first appeared in Cisco IOS Release 11.3 NA.
Example
The following example clears the counters for the modem at IP address 172.00.00.00:
Related Commands
clear cable modem reset
To remove a modem from the Station Maintenance List and reset the modem, use the clear cable modem reset privileged EXEC configuration command:
- clear cable modem {mac-addr | ip-addr | all} reset
Syntax Description
Default
Command Mode
Usage Guidelines
This command first appeared in Cisco IOS Release 11.3 NA. This command causes the link to the modem to drop. The modem responds by resetting itself. It can take up to 30 seconds for the modem to start the reset sequence.
Example
The following example removes the cable modem at 172.00.00.00 from the Station Maintenance List:
Related Commands
ping cable-modem
To determine whether a specific cable modem is on line, use the ping cable-modem privileged EXEC configuration command:
- ping cable-modem mac-addr
Syntax Description
Default
Command Mode
Usage Guidelines
This command first appeared in Cisco IOS Release 11.3 NA.
Example
The following example confirms that the cable modem at 172.00.00.00 is connected to the network and is operational:
show cable flap-list
To display the cable flap-list, use the show cable flap-list privileged EXEC configuration command:
- show cable flap-list [sort-flap | sort-time]
Syntax Description
|
(Optional) Sort by number of times the cable modem has flapped. |
|
|
(Optional) Sort most recent time the cable modem is detected to have flapped. |
Default
Command Mode
Usage Guidelines
This command first appeared in Cisco IOS Release 11.3 NA.
Sample Display
The following displays show the return for flap-list tables sorted by MAC address and by time:
Related Commands
show cable modem
To view configuration settings on the Cisco uBR7246, use the show cable EXEC command:
- show cable modem [ip-address | mac-address]
Syntax Description
Default
Command Mode
Usage Guidelines
This command first appeared in Cisco IOS Release 11.3 XA.
This command displays information on all cable modems or a particular cable modem on the network.
Sample Display
The following are sample outputs from the show cable modem command:
Table 4 describes the fields shown in the show cable modem display.
Related Commands
show cable burst-profile
show cable modulation-profile
show cable privacy
show cable qos
show cable spectrum-group
show cable modulation-profile
To display modulation profile group information, use the show cable modulation-profile privileged EXEC command:
- show cable modulation-profile [profile] [iuc-code]
Syntax Description
|
(Optional) Internal usage code. Valid values are: initial Initial Ranging Burst |
Default
Command Mode
Usage Guidelines
This command first appeared in Cisco IOS Release 11.3 XA.
This command displays modulation profile group information. A modulation profile is a collection of six burst profiles that are sent out in an upstream channel descriptors (UCD) message to configure a modem's transmit parameters for the following upstream message types: request, initial maintenance, station maintenance, short grant, and long grant.
Sample Display
The following is sample output from the show cable modulation-profile command:
length enco T CW seed B time CW offset
bytes size size size short
1 initial qpsk 128 no 0x5 0x22 0x152 0 48 no yes 0
1 station qpsk 128 no 0x5 0x22 0x152 0 48 no yes 0
1 short qpsk 72 no 0x5 0x4B 0x152 0 8 no yes 48
Table 5 describes the fields shown in the show cable modulation-profile display.
Related Commands
show cable burst-profile
show cable modem
show cable privacy
show cable qos
show cable spectrum-group
show cable qos permission
To display the status of permissions for changing QoS tables, use the show cable qos permission privileged EXEC configuration command:
- cable qos permission
Syntax Description
This command has no keywords or arguments.
Command Mode
Usage Guidelines
This command first appeared in Cisco IOS Release 11.3 NA.
Sample Displays
The following example displays the output of the show cable qos permission command:
Table 6 describes the fields shown in the show cable qos permission displays.
Related Commands
cable qos permission
cable qos profile
show qos profile
show cable qos profile
To display QoS profiles, use the show cable qos profile privileged EXEC configuration command:
- show cable qos profile service class
Syntax Description
Default
Command Mode
Usage Guidelines
This command first appeared in Cisco IOS Release 11.3 NA.
Sample Displays
The following example displays the QoS tables for profiles 1, 2, 3, and 4:
Table 7 describes the fields shown in the show cable qos profile displays.
| Field | Description |
|---|---|
|
Reports yes if Baseline Privacy is enabled for this QoS profile. Reports no if Baseline Privacy is not enabled for this Qos profile. |
Related Commands
cable qos permission
cable qos profile
show cable qos permission
show cable spectrum-group
To display information about spectrum groups, use the show cable spectrum-group privileged EXEC configuration command:
- show cable spectrum-group [groupnum]
Syntax Description
|
(Optional) Display information about the specified group number. If no group number is specified, information for all spectrum groups is displayed. |
Default
Command Mode
Usage Guidelines
This command first appeared in Cisco IOS Release 11.3 XA.
Sample Displays
The following are sample outputs from the show cable spectrum-group command for the upstream spectrum group named sales:
Table 8 describes the fields shown in the show cable spectrum-group displays.
Related Commands
show cable burst-profile
show cable modem
show cable modulation-profile
show cable privacy
show cable qos
show controllers cable
To display information about a specific cable modem card slot's interface controllers, use the show controllers cable privileged EXEC command:
- show controllers cable slot/port [upstream] [port]
Syntax Description
|
Slot number/port number indicating the location of the Cisco MC11 cable modem card. |
|
Default
Command Mode
Usage Guidelines
This command first appeared in Cisco IOS Release 11.3 XA and was modified in release 12.0(2)XC.
Sample Display
The following is sample output from the show controllers cable upstream command for the modem located in slot 4, port 0:
Table 9 describes the fields shown in the show controllers cable upstream display.
Related Commands
show interface cable
To display cable interface information, use the show interface cable privileged EXEC command:
- show interface cable slot/port [downstream | upstream]
Syntax Description
Default
Command Mode
Usage Guidelines
This command first appeared in Cisco IOS Release 11.3 XA.
Sample Display
The following is sample output for the cable modem located in slot 6/port 0 from the show interface cable command:
0 output buffer failures, 0 output buffers swapped out
Table 10 describes the fields shown in the show interface cable display.
The following is sample output for the downstream cable interface of slot 6 on port 0 from the show interface cable downstream command:
Table 11 describes the fields shown in the show interface cable downstream display.
| Field | Description |
|---|---|
|
Sum of all errors that prevented downstream transmission of packets out of this interface. |
The following is sample output for the upstream cable interface located in slot 6/port 0 from the show interface cable upstream command:
Table 12 describes the fields shown in the show interface cable upstream display.
Related Commands
show interface cable sid
show interface cable signal-quality
show interface cable sid
To display information by service identifier (SID) of each cable modem on the network, use the show interface sid privileged EXEC command:
- show interfaces cable slot/port sid [sid-number]
Syntax Description
|
Identifies the Cisco uBR7200 chassis slot number and downstream port number. Valid values are from 3 to 6. |
|
Default
Command Mode
Usage Guidelines
This command first appeared in Cisco IOS Release 11.3 XA. Data transport over the RF link uses the registered SID address rather than the Ethernet address. This allows multiple hosts to access the network via a single cable modem.
Sample Display
The following are sample outputs from two uses of the show interface cable sid command:
If the value for the QoS group in the display appears as 0, it indicates that a temporary SID has been assigned to a cable modem that is in the process of connecting to the network:
If there are no cable modems connected to the cable interface you have selected, the display will appear as follows:
Note Use the show cable qos command to examine the actual quality of service parameters assigned to the QoS group numbers.
Table 13 describes the fields shown in the output for the show interface cable sid displays.
| Field | Description |
|---|---|
|
"Disable" means that the SID has been administratively disabled. "Enable" is the normal state. |
|
|
When the SID was created, number of seconds since system booted. |
|
Related Commands
show interface cable signal-quality
show interface cable signal-quality
To display information about the signal quality, use the show interface cable signal-quality privileged EXEC command:
- show interface cable slot/port signal-quality
Syntax Description
|
Identifies the Cisco uBR7200 chassis slot number and downstream port number. Valid values are from 3 to 6. |
Command Mode
Usage Guidelines
This command first appeared in Cisco IOS Release 11.3 XA.
Sample Display
The following is sample output from the show interface signal quality command:
Table 14 describes the fields shown in the show controllers cable upstream display.
| Field | Description |
|---|---|
Related Commands
show interface
show interface cable
show interface cable sid
test cable atp cable
To run the acceptance test procedure on a port, use the test cable atp cable privileged EXEC configuration command:
- test cable atp cable slot/port MAC-address category test-id
Syntax Description
Default
Command Mode
Usage Guidelines
This command first appeared in Cisco IOS Release 11.3(6)NA. You should read and understand the ATP documentation before using this command.
The ATP tests are organized into categories such as PHY, MP, MAC, and so forth. Tests within each category are labeled MP01, MP02, ..., MAC01, MAC02, and so forth. If you run a test from the CLI, you can omit the leading zero in the test ID.
In this release, Cisco supports only a subset of all of the tests.
Examples
The following example tests the upstream cable interface located in slot 2/port 0 at MAC address 1.1.1. The test specified is MAC-PHY test 4 (MP-04).
Some tests, such as the one shown below, produce volumious output:
Debug Commands
The following debug cable commands have been added to or modified in this release of the Cisco uBR7246 and are available to help you troubleshoot the cable interfaces:
For information on other debug cable commands, refer to Voice, Video, and Home Applications Configuration Guide.
debug cable mac
Use the debug cable mac EXEC command to display MAC-layer information for the specified cable modem. The no form of this command disables debugging output.
- debug cable mac
no debug cable mac
Syntax Description
This command has no keywords or arguments.
Default
Command Mode
Usage Guidelines
This command first appeared in Cisco IOS Release 11.3 NA.
Note Do not use this command if you have a large number of modems on your network. The Cisco uBR7246 will become flooded with console printouts.
Example
The following example shows the return for the MAC layer:
Related Commands
debug cable map
Use the debug cable map EXEC command to display map debugging messages. The no form of this command disables debugging output.
- debug cable map
no debug cable map
Syntax Description
This command has no keywords or arguments.
Default
Command Mode
Usage Guidelines
This command first appeared in Cisco IOS Release 11.3 NA.
Example
The following example displays all the MAP messages with and without data grants:
Related Commands
What to Do Next
For more information on the Cisco uBR7246, refer to the Voice, Video, and Home Applications Configuration Guide.
For instructions on the advanced configuration of the port adapters installed in your Cisco uBR7246, refer to the respective installation documents that shipped with each port adapter. This documentation is also available on the Cisco Documentation CD-ROM and on Cisco Connection Online (CCO).
For instructions on the advanced configuration of the cable modem cards, refer to the document Cisco uBR7246 Universal Broadband Router Cable Modem Card Installation and Configuration This document accompanies every Cisco cable modem card that is shipped from the factory as an installed item in a Cisco uBR7246 or as a field replaceable unit (FRU). The document is also available on the Cisco Documentation CD-ROM and on CCO.
