866vae no sync VDSL German Telekom

_networker_ · ‎05-16-2013

Hello,

my 866vae Router doesn't sync on a regular VDSL50 German Telekom Line (with regular Phone and a dsl splitter, no voip)!?

IOS is 15.1(4)M4. "show controllers vdsl 0" shows, that the modem status toggles:

Modem Status: Handshake

Modem Status: Idle

Modem Status: Unknown

I tried to configure the controller to fix to vdsl2

controller VDSL 0

operating mode vdsl2

but that didn't help. Modem Firmware is

Modem FW Version:23i

Modem PHY Version:B2pvC032b.d23i

IOS image file is c860vae-ipbasek9-mz.151-4.M4.bin

How to proceed next? Are there any commands or debug commands whcih can help?

If i remember correctly, a 886va Router was able to sync on this line...

Subeh Sharma · ‎05-17-2013

Hi,

With any DSL flavor, the main thing for the DSL to come up is with its compatibility with the DSLAM on the ISP end. If the two are incompatible then no matter what we do, they DSL controller won't come up. In case of 886vae, please check this link for various DSLAM models which are tested and confirmed compatible with 866vae routers.

http://www.cisco.com/en/US/prod/collateral/routers/ps380/data_sheet_c78-693249.html

Also, please check with you ISP on the make and model of the DSLAM they have for you and let us know. Only after checking this compatibility we can proceed further.

886va and 866vae have different set of DSLAMs compatibility so it can be the reason for the same link working fine with 886va.

http://www.cisco.com/en/US/prod/collateral/routers/ps380/data_sheet_c78_459542_ps380_Products_Data_Sheet.html

Regards,

Subeh

_networker_ · ‎05-17-2013

Thank you Subeh for pointing out the differences of the two models.

I have an interesting update:

After changing the cable from the router to the splitter i get a link now (the bundle cable was rj11-rj11 and maybe the rj11 connector wasn't correctly fitted in the rj45 connector of my splitter)!

Unfortunately, now i have an extremely bad connection regarding overall througput. I roughly get 15 Mbit Down and 3 Mbit Up on my 50 / 10 Connection. I`ve checked everything and the bad performance is directly related to the cisco router. With the original Router which i received from Deutsche Telekom (a Speedport W722V) i get 42 Mbit and 8,5 Mbit with the same sites as above).

Here is the output after executing the "show controllers vdsl 0" command:

Controller VDSL 0 is UP

Daemon Status: NA

XTU-R (DS) XTU-C (US)

Chip Vendor ID: 'BDCM' 'IFTN'

Chip Vendor Specific: 0x0000 0xA440

Chip Vendor Country: 0xB500 0xB500

Modem Vendor ID: 'CSCO' 'IFTN'

Modem Vendor Specific: 0x4602 0xA440

Modem Vendor Country: 0xB500 0xB500

Serial Number Near: XXXXXX 866VAE 15.1(4)M

Serial Number Far:

Modem Version Near: 15.1(4)M

Modem Version Far: 0xA440

Modem Status: TC Sync (Showtime!)

DSL Config Mode: AUTO

Trained Mode: G.993.2 (VDSL2) Profile 17a

TC Mode: PTM

Selftest Result: 0x00

DELT configuration: disabled

DELT state: not running

Trellis: ON ON

Line Attenuation: 0.0 dB 0.0 dB

Signal Attenuation: 0.0 dB 0.0 dB

Noise Margin: 19.1 dB 11.4 dB

Attainable Rate: 108912 kbits/s 23540 kbits/s

Actual Power: 13.9 dBm - 6.3 dBm

Per Band Status: D1 D2 D3 U0 U1 U2 U3

Line Attenuation(dB): 9.6 20.2 34.2 4.4 16.5 25.9 N/A

Signal Attenuation(dB): 9.6 20.2 34.2 4.4 16.2 25.5 N/A

Noise Margin(dB): 19.3 19.0 19.1 12.9 11.6 11.3 N/A

Total FECS: 96319 151518

Total ES: 35 16

Total SES: 32 16

Total LOSS: 25 0

Total UAS: 307 307

Total LPRS: 0 0

Total LOFS: 24 0

Total LOLS: 0 0

Bit swap: 0 0

Full inits: 5

Failed full inits: 0

Short inits: 0

Failed short inits: 0

Firmware Source File Name (version)

-------- ------ -------------------

VDSL embedded N/A (0)

Modem FW Version: 23i

Modem PHY Version: B2pvC032b.d23i

DS Channel1 DS Channel0 US Channel1 US Channel0

Speed (kbps): 0 51392 0 10048

Previous Speed: 0 51392 0 10048

Reed-Solomon EC: 0 576 0 1010

CRC Errors: 0 16262 0 0

Header Errors: 0 0 0 0

Interleave (ms): 0.00 6.00 0.00 6.00

Actual INP: 0.00 2.01 0.00 3.00

Training Log : Stopped

Training Log Filename : flash:vdsllog.bin

Are there any (hidden) commands to stabilize the connection? Perhaps it would be better if the controller would sync to a lower down/up rate but without errors?

Subeh Sharma · ‎05-17-2013

Hi,

I could see the line is being sync'd at 51392 kbps. What is the desired speed of your ISP DSL connection? Also have you tried upgrading the firmware of the router with the latest available on the cisco site?

Regards,

Subeh

_networker_ · ‎05-18-2013

Update: after using the newest Firmware VAE_AB_35j_23jE.bin the performance has dramatically increased. Now i get 35-45 Mbit Down and 6-8 Mbit Up. These results are simialr to the Original ISP Router.

I didnt't expect that you can get such dramatic performance differences, only by using another firmware!?

Another question: What about the other counters in the following output (FECS, ES, UAS, Reed Solomon EC). They`re increasing. Does it matter? Or is it correct, that only "CRC Errors" und "header Errors" really matter, because all other problems are solved by error-correction algorithms?

Are there other options to improve the connection? Is it possible to reduce the maximal speed and get more overall stability (Other Routers offer such Configuration Options)

#####

Controller VDSL 0 is UP

Daemon Status: NA

XTU-R (DS) XTU-C (US)

Chip Vendor ID: 'BDCM' 'IFTN'

Chip Vendor Specific: 0x0000 0xA440

Chip Vendor Country: 0xB500 0xB500

Modem Vendor ID: 'CSCO' 'IFTN'

Modem Vendor Specific: 0x4602 0xA440

Modem Vendor Country: 0xB500 0xB500

Serial Number Near: XXXXX 866VAE 15.1(4)M

Serial Number Far:

Modem Version Near: 15.1(4)M

Modem Version Far: 0xA440

Modem Status: TC Sync (Showtime!)

DSL Config Mode: AUTO

Trained Mode: G.993.2 (VDSL2) Profile 17a

TC Mode: PTM

Selftest Result: 0x00

DELT configuration: disabled

DELT state: not running

Trellis: ON ON

Line Attenuation: 0.0 dB 0.0 dB

Signal Attenuation: 0.0 dB 0.0 dB

Noise Margin: 19.2 dB 12.3 dB

Attainable Rate: 109156 kbits/s 24668 kbits/s

Actual Power: 14.0 dBm - 6.3 dBm

Per Band Status: D1 D2 D3 U0 U1 U2 U3

Line Attenuation(dB): 9.6 20.2 34.1 4.3 16.5 25.8 N/A

Signal Attenuation(dB): 9.6 20.2 34.1 4.3 16.2 25.4 N/A

Noise Margin(dB): 19.3 19.1 19.1 14.1 12.5 12.1 N/A

Total FECS: 23182 95335

Total ES: 0 3

Total SES: 0 3

Total LOSS: 0 0

Total UAS: 28 28

Total LPRS: 0 0

Total LOFS: 0 0

Total LOLS: 0 0

Bit swap: 28 0

Full inits: 1

Failed full inits: 0

Short inits: 0

Failed short inits: 0

Firmware Source File Name (version)

-------- ------ -------------------

VDSL user config flash:VAE_AB_35j_23jE.bin (0)

Modem FW Version: 23i

Modem PHY Version: B2pvC035j.d23i

DS Channel1 DS Channel0 US Channel1 US Channel0

Speed (kbps): 0 51392 0 10048

Previous Speed: 0 0 0 0

Reed-Solomon EC: 0 23182 0 95335

CRC Errors: 0 0 0 0

Header Errors: 0 0 0 0

Interleave (ms): 0.00 6.00 0.00 6.00

Actual INP: 0.00 2.01 0.00 3.00

Subeh Sharma · ‎05-18-2013

Glad to know that the you get better service after firmware upgrade. Actually, in DSL world, everything depends on few seconds in the begining of the connection when the line is being trained. This is the time when the router's DSL card and the ISP's chipset negotiate various parameters like speed, line condition etc. And the firmware carries special line of codes which helps in many scenarios like compatiblity with certain DSLAMs at ISP end, negotiating a better line rate, noise margin etc. So, Yes a firmware can play a BIG role in DSL world.

Coming back to your question, you shouldn't be concerned on FECS, ES etc. and you're right to conclude that the only counter you should be concentrating on should be CRC. Now, you can see this counter in 'show dsl int atm' output as well as 'show interface atm' output. The question is are these two counters same or different? and which one you should monitor. So, these CRC counters are different and corresponds to different stages of the circuit. Where CRC counter of 'show dsl int atm' shows CRC value while the line was getting trained and normally remains constat once the line is trained. Even if you see this counter increase even after the line trainup, it will not impact your speed and traffic flow as the upper ATM layers corrects this problem automatically. The CRC you see on the "show int atm' shows the CRC errors encountered while the actual trafffic flows like ping, ftp etc and should be carefully examined. You can check this link for how to troubleshoot these CRC errors:

http://www.cisco.com/en/US/tech/tk39/tk48/technologies_tech_note09186a00800c93ef.shtml

As for your question of reducing the speed for a better connectivity, this is not available to DSL Subscribers and can only be done by the ISP. Things to be careful about in a DSL connection:

1. Noise margin (should be >8dB)-->Show dsl int atm 0

2. Attenuation (should be <60)-->Show dsl int atm 0

3. CRC, Input errors--->Show interface atm

4. Total output drops --->Show interface atm

HTH

Subeh