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1265
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14
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DSL Output Connection Speed

hellspire69_2
Level 1
Level 1

Good Morning All,

I have just been given the responsibility of managing our adsl routers. I have a user complaining of speed issues, I have generated the output below. It states that I should have 8064mbps download rate? So I presume that their download rates should be 1MB/s download? I have done a through put test and they are getting 200kbps average which seems strange considering the output from show dsl interface atm0. The sites actual broadband test through a random website showed 4.7mbps download rate.

If anyone can help shed some light or why I am getting a slower rate that would be brilliant.

                ATU-R (DS)                      ATU-C (US)

Modem Status:    Showtime (DMTDSL_SHOWTIME)

DSL Mode:        ITU G.992.1 (G.DMT)

ITU STD NUM:     0x01                            0x01

Vendor ID:       'ALCB'                          'IFTN'

Vendor Specific: 0x0000                          0x71C8

Vendor Country:  0x00                            0xB5

Capacity Used:   91%                             53%

Noise Margin:     8.0 dB                         24.0 dB

Output Power:    20.0 dBm                        11.0 dBm

Attenuation:     20.0 dB                         12.0 dB

Defect Status:   None                            None

Last Fail Code:  Message error

Selftest Result: 0x49

Subfunction:     0x02

Interrupts:      1393 (1 spurious)

Activations:     128

SW Version:      3.8129

FW Version:      0x1A04

                 Interleave             Fast    Interleave              Fast

Speed (kbps):          8064                0           448                 0

Reed-Solomon EC:         95                0             1                 0

CRC Errors:               1                0             0                 0

Header Errors:            1                0             0                 0

Bit Errors:               0                0

BER Valid sec:            0                0

BER Invalid sec:          0                0

DMT Bits Per Bin

00: 0 0 0 0 0 0 0 2 4 5 5 5 6 7 8 7

10: 8 8 8 7 8 8 8 7 7 7 5 5 5 4 0 0

20: 0 0 0 0 0 0 A B B B B C C C C C

30: C C D D D D D D D D D D D D C D

40: D D D D C C D D D D D C D C C C

50: D D C C C C C C C C C 2 C C C C

60: C C C C C C C C C C C C C C C C

70: C C B B B B B B B B B B B B B B

80: B B B B B 0 B B B B B B B B B B

90: B B B 0 B B A A 0 B B B B B B B

A0: B B B A A A A A A A A A A A A A

B0: A A A A A A A A A A A A A A A 9

C0: 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9

D0: 9 9 9 9 A 9 9 9 9 9 9 9 9 9 9 9

E0: 9 9 9 8 9 9 9 9 9 9 9 9 9 9 8 8

F0: 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

11 Replies 11

paolo bevilacqua
Hall of Fame
Hall of Fame

Circuit appears poor and unstable.

Howe ver in practice 200 kB/s is decent result.

You can try updating IOS and/or DSl firmware first. There are various threads about.

Thanks Paolo,

You say that the circuit appears to be unstable. Where do you see this? I am new so any advice would be good

Dan

Activations: 128

Thanks for all the help Paolo its much appreciated from a novice like myself. Is there anything else other then the activations that would cause the slowness we are experiencing?

I have checked for information on Activations and it is scarce. What I did find only told me that it was a drop sync fault, is that enough to cause this speed impairment?

Thanks

D

It indicates that things are not working good.

Update IOS and or DSL FW and mentioned above.

Joseph W. Doherty
Hall of Fame
Hall of Fame

Disclaimer

The   Author of this posting offers the information contained within this   posting without consideration and with the reader's understanding that   there's no implied or expressed suitability or fitness for any purpose.   Information provided is for informational purposes only and should not   be construed as rendering professional advice of any kind. Usage of  this  posting's information is solely at reader's own risk.

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In   no event shall Author be liable for any damages whatsoever (including,   without limitation, damages for loss of use, data or profit) arising  out  of the use or inability to use the posting's information even if  Author  has been advised of the possibility of such damage.

Posting

Some times, shaping your egress to uplink's nominal capacity will improve throughput.  When shaping, often FQ/WFQ is sufficient to deal with congestion.  Some times advanced congestion management is useful too.

Disclaimer

The Author of this posting offers the information contained within this posting without consideration and with the reader's understanding that there's no implied or expressed suitability or fitness for any purpose. Information provided is for informational purposes only and should not be construed as rendering professional advice of any kind. Usage of this posting's information is solely at reader's own risk.

Liability Disclaimer

In no event shall Author be liable for any damages whatsoever (including, without limitation, damages for loss of use, data or profit) arising out of the use or inability to use the posting's information even if Author has been advised of the possibility of such damage.

Posting

I forgot to mention, besides QoS shaping (which often deals better with TCP bursting the the vendor's global FIFO), ADSL links are often PPPoE.  If yours is, allowing for the lost of the 8 bytes of the MTU, especially using adjust-mss, can result in much better TCP performance if you're currently fragmenting max size packets.

Robert Craig
Level 3
Level 3

Correct me if I'm wrong, but rarely will you see your ADSL connection reach its full potential because of line quality, distance from CO, and over subscription. Also, if memory serves me right, traditional ADSL has a max throughput of around 6mbps because of frequency bleed over on the copper. Anyone remember those figures? Been a while since I've dealt with DSL.

Rob

Sent from Cisco Technical Support iPhone App

Robert Craig wrote:

Correct me if I'm wrong, but rarely will you see your ADSL connection reach its full potential because of line quality, distance from CO, and over subscription. Also, if memory serves me right, traditional ADSL has a max throughput of around 6mbps because of frequency bleed over on the copper. Anyone remember those figures? Been a while since I've dealt with DSL.

"traditional ADSL" max downstream bandwidth is 8 Mbps, then with "Annex A" it can be up 12. Router selects the proper mode automatically. In this case no "Annex A" was negotiated with the DSLAM.

johnlloyd_13
Level 9
Level 9

hi,

in addition to what others have posted, you should also check the utilization using the show interface atmx command.

i've got clients complained speed issues, only to find out their upload bandwidth is maxed out. ADSL usually has upload speeds in kbps rates.

you should also report to your ISP to have the link checked due to high attentuation: 20.0 dB (DS).

Disclaimer

The  Author of this posting offers the information contained within this  posting without consideration and with the reader's understanding that  there's no implied or expressed suitability or fitness for any purpose.  Information provided is for informational purposes only and should not  be construed as rendering professional advice of any kind. Usage of this  posting's information is solely at reader's own risk.

Liability Disclaimer

In  no event shall Author be liable for any damages whatsoever (including,  without limitation, damages for loss of use, data or profit) arising out  of the use or inability to use the posting's information even if Author  has been advised of the possibility of such damage.

Posting

i've got clients complained speed issues, only to find out their upload bandwidth is maxed out. ADSL usually has upload speeds in kbps rates.

Yup, exactly!  If so, again, shaping for egress with better congestion management, as my first post noted, can sometimes improve performance.  For example, loosing groups of ACKs can be detrimental to ingress performance.

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