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Docsis 2.0 trouble

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Anonymous (not verified)
Docsis 2.0 trouble

hi there,

we have a Cisco CMTS UBR 10012 and Thomson TCM 420 cable modems running Eurodocsis standard

the problem is that we never get upload speeds over 2,7 mbit. does anybody have some experience about cisco ubr's and configuration running Docsis 2.0

the modem is showing MAC: Docsis 2.0 QOS: Docsis 1.1 channel width is at 6,4 mhz in the upstream running qam 64 - the modem shows that he is connected with QPSK in the upstream

any help would be great
kind regards
Simon

Anonymous (not verified)
Docsis 2.0 trouble

May be the problem in logical upstream channel settings?
Post UBR config here

cmcaldas
docsis 2.0 upstream

Sorry, I'm not a Cisco guy, but your upstream channel width says 6.4 followed by 1.6 Mhz wide? your modem file should have a max burst as well. in my setup I use 6.4Mhz wide running atdma. I couldn't attach a picture, so a link follows that shows 20.4 Mbps on my upstream with Ixia Qcheck. jperf is slightly better because it runs longer

http://photos1.hi5.com/0036/541/477/rlcDUp541477-02.jpg

Hari (not verified)
Have u tested throughput on

Hi cmcaldas,
Have u tested throughput on upstream port of CMTS or cable modem upstream ?

Can I have your cable modem config as well as CMTS configuration..plz
Harindra

cmcaldas
Upstream throughput

Hi Harindra,
I'm sorry for not checking the posts, I've been working on getting my docsis 3.0 working and the all the fun that goes with it lol
Please keep in mind, my setup is in a lab. but I have made changes in my modulation profile for noisy plant. I wish there was a way to attach to the post, but with Ixia Qcheck or Iperf on a domestic config on the upstream I average 14 Mbps and on my euro I can reach a little over 20 Mbps upstream.
send me an email and I can reply with the modem file, running config and snap shot from the Qcheck

Regards
Carl

cmcaldas@gmail.com

wittmann
Docsis 2.0 trouble

@Simon,

have you set DOCSIS2.0 enable at configfile?

Anonymous (not verified)
Docsis 2.0 trouble

here are the important config parts

ubr config:

cable modulation-profile 222 request 0 16 0 22 64qam scrambler 152 no-diff 64 fixed qpsk1 1 2048
cable modulation-profile 222 initial 5 34 0 48 64qam scrambler 152 no-diff 128 fixed qpsk1 1 2048
cable modulation-profile 222 station 5 34 0 48 64qam scrambler 152 no-diff 128 fixed qpsk1 1 2048
cable modulation-profile 222 a-short 6 76 6 22 64qam scrambler 152 no-diff 64 shortened qpsk1 1 2048
cable modulation-profile 222 a-long 8 231 0 22 64qam scrambler 152 no-diff 64 shortened qpsk1 1 2048
cable modulation-profile 222 a-ugs 8 231 0 22 64qam scrambler 152 no-diff 64 shortened qpsk1 1 2048

[cable interface]
cable tftp-enforce
no cable packet-cache
cable downstream annex A
cable downstream modulation 256qam
cable downstream frequency xxxxxxx
cable downstream channel-id 1
no cable downstream rf-shutdown
cable downstream rf-power 57
cable upstream 0 connector 4
cable upstream 0 frequency xxxxxxxx
cable upstream 0 docsis-mode atdma
cable upstream 0 channel-width 6400000 1600000
cable upstream 0 minislot-size 2
cable upstream 0 power-level 0
cable upstream 0 range-backoff 3 6
cable upstream 0 modulation-profile 222
cable upstream 0 equalization-coefficient

modem config:

Main
{
NetworkAccess 1;
BaselinePrivacy
{
AuthTimeout 10;
ReAuthTimeout 10;
AuthGraceTime 600;
OperTimeout 10;
ReKeyTimeout 10;
TEKGraceTime 600;
AuthRejectTimeout 60;
}
VendorSpecific
{
.
.
.
}
MaxCPE 5;
UsPacketClass
{
ClassifierRef 2;
ServiceFlowRef 2;
ActivationState 1;
IpPacketClassifier
{
DstPortStart 2727;
DstPortEnd 2727;

}
}
UsPacketClass
{
ClassifierRef 1;
ServiceFlowRef 2;
ActivationState 1;
LLCPacketClassifier
{
EtherType 0x030f16;
}
}
DsPacketClass
{
ClassifierRef 3;
ServiceFlowRef 4;
ActivationState 1;
IpPacketClassifier
{
IpProto 256;
DstPortStart 2427;
DstPortEnd 2427;
}
}
UsServiceFlow
{
UsServiceFlowRef 1;
QosParamSetType 7;
MaxRateSustained 10000000;
SchedulingType 2;
}
UsServiceFlow
{
UsServiceFlowRef 2;
QosParamSetType 7;
TrafficPriority 4;
SchedulingType 2;
}
DsServiceFlow
{
DsServiceFlowRef 3;
QosParamSetType 7;
MaxRateSustained 10000000;
}
DsServiceFlow
{
DsServiceFlowRef 4;
QosParamSetType 7;
TrafficPriority 4;
}
GlobalPrivacyEnable 1;
DocsisTwoEnable 1;
}

kind regards
Simon

Anonymous (not verified)
cm config settings

You cannot go any higher than 2.7Mbps. There is an issue with the chipset, so it cannot transfere more than 2.7Mbps pr. session - even though you can go higher when transfering from multiple modems at the same time.

About the doc 2.0 flag: This is enabled by default, so you don't need to set this. You will only set it to 0, if you want to disable 2.0...

There are some issues with the TCM420 as well, but I'm pretty sure that is the case here. Let me know if you purchase another CMTS, and still can't get the US rate any higher...

Anonymous (not verified)
Docsis 2.0 trouble

successfull tested a bandwith of 6MBit+ in the US
with a lower time slot and channel bw of 6,4 Mhz

Hari (not verified)
docsis 2.0 upload not more than 2.7 mbps

Hi simon,

can you tell me, how you able to upload more than of 2.7 mbps, i have configured same in my cm file but not able to reach more than of 2.7 mbps. how did you test 6 Mbps uload ?

show me your cmts and cm file configuration plz....

Anonymous (not verified)
6mbps +

That's strange. Guess I have mixed the different Cisco CMTS names. Pardon for that. But since you have managed to get the 6Mbps, I might help you to get a bit more...

What do you mean about timeslot? Is that the same as minislotsize? In that case, have you tried with both 2 and 4 slots?

You can also try with some other settings in the configfile:

UsServiceFlow {
UsServiceFlowRef 2;
QosParamSetType 7;
MaxConcatenatedBurst 4566;
MaxTrafficBurst 4566;
}

Note the MaxConcatenatedBurst and MaxTrafficBurst. Try with 1522 * X values, and see what gives you the best result.

Hari (not verified)
regarding docsis upstream not more than 2.7 mbps

can you tell me, how you able to upload more than of 2.7 mbps, i have configured same in my cm file but not able to reach more than of 2.7 mbps. how did you test 6 Mbps uload ? it's upstream port of CMTS or upstream speed of modem ?

show me your cmts and cm file configuration plz....

Harindra.

Wodec
Hi Simon,don't get mixed

Hi Simon,

don't get mixed up. The 2.7Mb is a very good result. This is the physical limmitation of Docsis.
OK Docsis 2.0 at qam64 equals 30Mb upstream theoretical, for the upstreamPORT. upstreamspeed of cablemodem is different of the upstreamport of your CMTS.

Try it, 5CM's at 2.7Mb =ok, 10CM's at2.7Mb = ok 20CM's at 2.7Mb = NOK

I have the same UBR, only i work with webstart modem's.

Hari (not verified)
more than 2.7 mbps

Hi Wodec,
That means we can't go more than 2.7 Mbps per modem ...is there any modem which is supporting more than 2.7 mpbs upstream.
How much you are getting in webstart modems?
But Simon is saying that he has tested 5.5 mbps behind cable modem ... how it's possible??

Hari.

racarvalho
More than 2,7Mbs per CM on UBR DOCSIS2.0

Hi all,

I finally can get 6Mb US, here's how ...

On UBR you need the IOS 123-23.BC or above (i'm using BC4).
Use the global command "cable upstream rate-adapt".
Now i can reach 26Mb/6Mb on my CM(SB5121) using a-tdma 16QAM on the upstream.
Beware that you're likely to have problems if you have more than 100 CM per US

RAC

buzzwork
Hey Simon, Did you ever this

Hey Simon,

Did you ever this this problem fixed because im having the same issues right now :)
Hope you can post it on this forum, thanks

Martin
DK

hinzoo
What version of firmware do

What version of firmware do You have on TCM420? Maybe You have to upgrade it?

buzzwork
Sorry, we use only Motorola

Sorry, we use only Motorola Surfboard 5101 modems in out setup, running :
SB5100E-2.3.1.8-SCM06-NOSH

Any one know if this software or even hw (chipset) has a "feature" of max US speed of 2-3mbit ?

Martin
DK

crsrikanth84
Need help on BSr 64K

Hi,
How do we configure dynamic SA for a multicast goup address in BSR 64K

Thanks in Advance ..

wittmann
Link to cisco
Hello everybody, maybe this link will also help: [url=http://www.cisco.com/warp/public/109/data_thruput_docsis_world_19220.shtml]Link [/url]

regards,

wittmann

P.S. Sorry for my poor english ;)

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