VeEX VePal CX350, Руководство пользователя

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MAC Selection:
supports two Cable Modem MAC Addresses. Typically use MAC1 for all tests.
MAC Address:
This can be set to default (a pre-programmed registered unique MAC address), or it can be manually entered to clone a specific customer modem. If manual
is selected, tap on the MAC address field to enter your desired MAC address. Caution must be taken that if the CMTS has the BPI+ enabled, manually entered a cloned
MAC address may not be able to register successfully due to the registration certificate of the cable modem is internally coded per pre-programmed MAC address.
DOCSIS Mode:
DOCSIS 3.0:
is recommended
DOCSIS 2.0:
for legacy DOCSIS 2.0 systems
DOCSIS 1.1/1.0:
for legacy DOCSIS 1.X systems
Test Mode:
Terminate:
terminate mode
Pass Through:
emulating a stand-alone Cable Modem. Once the Cable Modem goes online, you can connect a PC to the 10/100/1000 Ethernet test port at the top
of the unit. The meter will automatically assign a Client IP address to the PC. Then with the PC, you can access the internet. This mode helps sectionalize and
troubleshoot issues in the customer premises (e.g. replace the actual cable modem).
Always On:
terminate mode and also enables the Cable Modem to remain online when you exit from the Cable Modem. This allows you have online connectivity
while using other features, such as Remote View and V300 R-Server access.
Once these settings are completed, press Connect. Once connect is pressed, the test set will go directly to the result page. Each step of the connection process is listed. As
a step is performed, an "in progress" indicator informs the user of the current status.
After a step is completed, a Pass or Fail status is provided. If any one of the steps fails during the connection process, the cable modem will stop and declare a failed
connection. At this point, the user can either choose to reset the test and try again, or go back to setup and verify the settings.
DOCSIS Cable Modem (CM) Initialization Sequence
Cable Modem (CM) Connection Procedure and Training Sequence:
1. CM scans the Downstream (DS) spectrum for a valid DOCSIS signal (either 64QAM or 256QAM). This can be a time consuming step if the CM is not on a channel.
2. CM demodulates the DOCSIS signal and looks for a SYNC message.
3. CMTS periodically broadcasts Upstream (US) Channel Descriptors (UCD) over the DS channel, from which a CM learns its assigned upstream operational frequency.
The CM in turn scans for these UCD messages, which instructs the CM how to configure a burst profile (frequency, modulation, and burst parameters).
The CM has now established both a US and a DS frequency.
4. CMTS periodically transmits US bandwidth allocation maps (MAP) in shared time slots in the DS direction. The CM looks for these MAP messages, which list the
granted and contended Time Slots (TSs) for US communication.
5. CMTS assigns a temporary Service Identifier (SID) to the CM, which initiates a coarse power ranging and time synchronization process.
The first Upstream burst that the CM sends is the initial maintenance - the CMTS responds with the Range-Response (RGN-RSP) message for frequency, power,
and timing settings.
6. CMTS periodically sends keep-alive messages to verify link continuity between itself and all CM units in the same domain. When a CM receives its first keep-alive
message, it reverts to a fine power ranging.
7. CM now forwards a bandwidth request to the CMTS, which in turn forwards a grant to the CM, permitting it to forward upstream information in allocated time slots.
8. CM now makes a DHCP discovery followed by a DHCP request. The CMTS forwards a DHCP acknowledgment from the DHCP server containing an IP address, a
default gateway, the addresses of a TFTP and TOD server, and a TFTP configuration file name.
9. CM now initiates the TOD and TFTP process. From the TFTP server, the CM receives a configuration file containing QoS, security, applicable frequency assignments
and any new software images.
10. CM forwards TFTP configuration file to the CMTS and initiates a registration request. If the configuration file is valid, the CMTS assigns the CM a permanent SID and
registers the CM to online status.
11. Following registration, the CM optionally initiates the activation of the 56-bit DES encryption algorithm to provide security between the CMTS and itself over the cable
plant.
12. CM is now operational and online.
Cable Modem Connection Process 1
CX350 e-Manual D07-00-037 RevC01 Page 36 of 81