The Vendor-Specific Information Field (VSIF) contains one or more defined sub-fields. The sub-fields are entered in the VSIF as a series of back-to-back Type-Length-Values (TLVs) decimal octets.
The following table lists the vendor-specific sub-fields currently supported in the Cisco cable modem reference design:
|
Sub-Field |
Type |
Length |
Value |
Usage |
|
Vendor ID |
8 |
3 bytes |
The first three octets of the cable modem MAC address. |
The Vendor ID attribute determines the vendor to which this vendor-specific information applies. The Vendor ID MUST be the first TLV in the VSIF. |
|
Static Downstream Frequency |
1 |
4 bytes |
The static downstream frequency. |
When the Static Downstream Frequency is specified, the modem will use only the specified frequency, and will not scan for other channels. |
|
Sync Loss Timeout |
2 |
4 bytes |
The maximum tolerance for sync loss. |
The Sync Loss Timeout option configures the modem to tolerate sync loss for up to the specified number of milliseconds. |
|
Update Boot Monitor Image |
3 |
n bytes |
A string of up to 255 bytes that is the name of a Boot Monitor image to download. |
Permits field updates of the Boot Monitor image in the Boot Monitor portion of flash memory bank 1. The specified string is the name of the Boot Monitor image to download. If the specified Boot Monitor image name differs from the image currently in flash memory, the new image is downloaded from the TFTP server to RAM and then written directly to flash memory bank 1. If the update succeeds, the modem reboots after the download. If a VxWorks system image update is also indicated by the configuration file, both updates are attempted before a reboot. As of build 32, all Boot Monitor images must be stamped with a checksum prior to being downloaded to guard against corrupting flash memory. This includes Boot Monitor images downloaded by any of the following means:
|
|
Power Backoff |
4 |
2 bytes |
The desired number of dB. |
The Power Backoff option configures the cable modem to lower power by the specified number of dB, whenever restarting the ranging process. |
|
Update Factory System Image |
9 |
1 byte |
1 |
Updates factory supplied system image in flash memory bank 1 with the system image in flash memory bank 2. Update begins only after the cable modem is successfully booted and operational from the system image in flash memory bank 2, and if the name of the system images in the two banks are different. |
The Cisco DOCSIS CPE Configurator accepts only dotted decimal input for the VSIF. For example, given the following VSIF values:
|
Vendor ID Number |
00 e0 1e (hex) |
0.224.30 (dotted decimal) |
|
Static Downstream Frequency |
92250000 (decimal) |
5.127.159.144 (dotted decimal) |
|
Sync Loss Timeout |
10000 (decimal) |
39.16 (dotted decimal) |
|
Update Boot Monitor Image |
bootrom.cnf (ASCII) |
98.111.111.116.114.111.109.46.99.110.102 (dotted decimal) |
|
Update Factory System Image |
1 (decimal) |
1 (dotted decimal) |
Enter the following string in the Vendor-Specific Info field:
8.3.0.224.30.1.4.5.127.159.144.2.4.0.0.39.16.3.11.98.111.111.116.114.111.109.46.99.110.102.4.2.0.6.9.1.1
where:
|
8.3.0.224.30 |
is the Vendor ID option |
|
1.4.5.127.159.144 |
is the Static Downstream Frequency option |
|
2.4.0.0.39.16 |
is the Sync Loss Timeout option |
|
3.11.98.111.111.116.114.111.109.46.99.110.102 |
is the Update Boot Monitor Image option |
|
4.2.0.6 |
is the Power Backoff option |
|
9.1.1 |
is the Update Factory System Image option |
For additional information, refer to the DOCSIS Radio Frequency Interface Specification (SP-RFI-I04-0980724).
The following table lists Cisco's and its partner's Vendor IDs. Enter the vendor-specific Vendor ID in the Vendor ID field.
|
Vendor ID |
CPE Device |
|
00:00:c0 |
Cisco QoS dummy vendor ID |
|
00:50:73 |
Cisco uBR904 Cable Access Router |
|
00:d0:58 |
Cisco uBR924 Cable Access Router |
|
00:90:96 |
Askey |
|
00:90:7b |
Etech |
|
00:00:f0 |
Samsung |
|
08:00:46 |
Sony |