Juniper Networks G10 CMTS manual Cable Modem Throughput is Slow, User@host show cable modem

Ideal HFC Plant Configuration Issues

•	! The cable modem received a configuration file, but the contents of the file are not valid.
•	Ensure the configuration settings are valid and are consistent with the DOCSIS
•	specifications.
•
•	! The cable modem timed out waiting for the time of day (TOD) server to respond. Newer
•	cable modems continue the registration process while continuing to retry the TOD
•	request. However, some older cable modems do not attempt to register if they time out
•	while waiting for a TOD response. The TOD timeout might occur if the TOD server IP
•	address provided in the DHCP response was incorrect.
•
•	A high IM value in the flap list can be an indication of TFTP, configuration file, or registration
•	issues.
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•Cable Modem Throughput is Slow

•
•	If the throughput of a cable modem seems slow, the cause might be one or more of the
•	following:
•
•	! The DOCSIS 1.0 Class of Service Configuration Setting (for DOCSIS 1.0) or the
•	Upstream Service Flow Configuration Setting and the Downstream Service Flow
•	Configuration Setting fields (DOCSIS 1.1) of the configuration file are limiting the
•	maximum upstream and downstream bandwidth of the cable modem. If necessary,
•	increase the parameters within these fields in the configuration file to increase the cable
•	modem’s throughput.
•
•	To determine the maximum bandwidth settings for a cable modem, issue the show
•	cable modem command to determine the QoS profile for a cable modem:
•
•	user@host> show cable modem
•
•	Interface Us Prim		Online		Timing Rec QoS BPI IP-Address					MAC-Address
•	Reg Modul	Sid	State		Offset Power
•
	ca-0/2/0	0 36	init(rc)		585	0.0	1 Off 10.27.1.101
•
	00:40:36:09:44:EB 1.0 TDMA
•
•	In this example, the cable modem uses QoS profile 1. Then issue the show cable
•
	qos-profilecommand to display the characteristics of QoS profile 1:
•
•	user@host> show cable qos-profile 1
•
•	Service	Prio	Max	Guarantee			Max	Max tx	Create Baseline
•
	class	upstream			upstream	downstream		burst	by	privacy
•		bandwidth		bandwidth		bandwidth				enable
•	1	0	1000000		0	10000000		0	cmts	no
•
•	The cable modem’s maximum upstream bandwidth is 1 Mbps and its maximum
•	downstream bandwidth is 10 Mbps.
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152 JUNOSg 3.0 G10 CMTS Hardware Guide