Slow ubr7200

I am working with a customer who has a Cisco CMTS uBR7246 with a DOCSIS Modem card that has 1 Down and 6 up.

Up until two months ago he said everything was working fine. Then suddenly, everything started running slow. (Of course he claimed nothing was changed!)

I am testing the CMTS with a client machine (connected to a modem) sending and receiving data to/from a server that is connected to the ethernet interface of the CMTS. If the QOS for the downstream is set to

10M, I get about 2M. If it is set to 1M, I get about 512K. Upstream values are working correctly.

The customer has a cold standby uBR with the same hardware, so I set it up with the same configuration, using a separate diplex filter and quam to hook it to 3 test cable modems. I got the same result.

I suspect there is something freaky in the configuration, but I cannot find it. If anyone can help, I would appreciate it!

Configurations are below.

TIA!!!!

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===== Cable Modem Configuration ================== Main { NetworkAccess 1; ClassOfService { ClassID 3; MaxRateDown 10485760; MaxRateUp 1048576; PriorityUp 7; GuaranteedUp 0; MaxBurstUp 0; PrivacyEnable 0; } MaxCPE 7; }

====ubr7200 config========================= ! version 12.0 service timestamps debug uptime service timestamps log uptime service password-encryption ! hostname standby7200 ! enable password 7 ******************* ! cable spectrum-group 1 frequency 24000000 cable modulation-profile 2 request 0 16 1 8 qpsk scrambler 152 no-diff

64 fixed uw16 cable modulation-profile 2 initial 5 34 0 48 qpsk scrambler 152 no-diff 128 fixed uw16 cable modulation-profile 2 station 5 34 0 48 qpsk scrambler 152 no-diff 128 fixed uw16 cable modulation-profile 2 short 6 75 6 8 16qam scrambler 152 no-diff 144 fixed uw8 cable modulation-profile 2 long 8 220 0 8 16qam scrambler 152 no-diff 160 fixed uw8 cable modulation-profile 8 request 0 16 1 8 qpsk scrambler 152 no-diff 64 fixed uw16 cable modulation-profile 8 initial 5 34 0 48 qpsk scrambler 152 no-diff 128 fixed uw16 cable modulation-profile 8 station 5 34 0 48 qpsk scrambler 152 no-diff 128 fixed uw16 cable modulation-profile 8 short 6 75 6 8 16qam scrambler 152 no-diff 144 fixed uw8 cable modulation-profile 8 long 8 220 0 8 16qam scrambler 152 no-diff 160 fixed uw8 no cable qos permission create no cable qos permission update cable qos permission modems cable time-server clock timezone EST -4 ip subnet-zero ip cef ip dhcp-server 172.16.1.15 ! ! ! interface FastEthernet0/0 ip address 172.16.1.3 255.255.255.0 ip helper-address 172.16.1.15 no ip directed-broadcast no ip mroute-cache full-duplex ! interface Cable3/0 ip address 10.255.255.1 255.255.255.0 secondary ip address 10.255.254.1 255.255.255.0 ip directed-broadcast ip helper-address 172.16.1.15 no ip mroute-cache no keepalive cable dhcp-giaddr primary cable downstream rate-limit token-bucket shaping cable downstream annex B cable downstream modulation 64qam cable downstream interleave-depth 32 cable downstream frequency 675000000 cable upstream 0 frequency 24000000 cable upstream 0 power-level 0 cable upstream 0 modulation-profile 2 no cable upstream 0 shutdown cable upstream 1 frequency 24000000 cable upstream 1 power-level 0 no cable upstream 1 shutdown cable upstream 2 frequency 24000000 cable upstream 2 power-level 0 no cable upstream 2 shutdown cable upstream 3 frequency 24000000 cable upstream 3 power-level 0 no cable upstream 3 shutdown cable upstream 4 frequency 24000000 cable upstream 4 power-level 0 cable upstream 4 modulation-profile 2 no cable upstream 4 shutdown cable upstream 5 frequency 24000000 cable upstream 5 power-level 0 no cable upstream 5 shutdown ! ip classless ! snmp-server engineID local 0000000902000002FC845400 snmp-server community ciscosnmp RW snmp-server community public view v1default RO snmp-server community ralph RO snmp-server trap-source FastEthernet0/0 snmp-server location nu snmp-server enable traps isdn call-information snmp-server enable traps hsrp snmp-server enable traps config snmp-server enable traps entity snmp-server enable traps envmon snmp-server enable traps cable snmp-server enable traps bgp snmp-server enable traps frame-relay snmp-server enable traps rtr snmp-server host 172.16.1.15 version 2c public ! ! line con 0 password 7 ********************** transport input none line aux 0 line vty 0 4 password 7 ********************** login ! end ===========================================================
Reply to
Charles Deling
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Hi Charles,

Aren't you talking about the Comcast? About two months ago they did something in Connecticut, and now I have about 1-1.5 Mb Downstream (from the Client side), and only 80-100Kb upstream. And they tell me that "everything is OK with them... :-(((

Mike

formatting link

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Reply to
CiscoHeadsetAdapter.com

No. I have no relationship with Comcast or that area of the country.

CiscoHeadsetAdapter.com wrote:

Reply to
Charles Deling
  1. change MaxBurstUp to 1600
  2. check duplex/speed settings for yours FE in ubr and switch/comp
  3. show me result of "sh cable modem MAC ver" for this modem which you tested.

-- KriS

Reply to
KriS

Done - no change

Done - both the UBR and the switch it is connected to is set to 100MB Full Duplex - (note: the switch is _not_ set to AUTO, it is set to Full Duplex)

There is no "sh cable modem MAC ver" command in this version of ios. There is only "sh cable modem MAC"

show cable modem 0013.71b5.264c Interface Prim Online Timing Rec QoS CPE IP address MAC address Sid State Offset Power Cable5/0/U4 14 online 1325 0.50 4 1 10.255.254.4

0013.71b5.264c

Thank you!

Reply to
Charles Deling

Which IOS ver you've got?

Show me result of: sh cable modem MAC phy sh cable qos prof (you can show me only profile 4)

-- KriS

Reply to
KriS

One more thing - why I don't see interface C5/0 in running config from first post? Modem is on C5/0 upstream 4 but in cfg I've se onl c3/0

-- KriS

Reply to
KriS

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