Hi all,
I upgraded my DSL to MAX speed (it should be 8 MBit/s) however my bax stable bandwidth has been tested at 2048 Kbit/s. Despite this I understand that the line provider (British Telecom) configures the DSLAM to sync at the maximum speed.
The downstream rate varies between 4200 and 3200 Kbit/s depending on the time of the day and the line noise (I guess).
Now, here is the problem. Often it happens that the Noise margin falls below 0 dB, when this happens the line re-syncronizes at a lower speed, only to re-sync again automatically at a higher speed when the line quality allows it. When this happens, I loose the connection for a few seconds and any TCP connection is lost (annoying).
I would like to set the downstream rate to a lower speed in order not to incur in these re-syncronizations.
How do I do this on a Cisco 3620 + WIC1-DSL without asking the ISP or line provider? Can I limit the downstream DSL to a fixed rate from my end?
Here is my current configuration:
! interface ATM1/0 no ip address no ip redirects no ip proxy-arp ip route-cache flow no atm ilmi-keepalive bundle enable ! dsl operating-mode itu-dmt hold-queue 224 in ! interface ATM1/0.1 point-to-point no ip redirects no ip proxy-arp pvc 0/38 encapsulation aal5mux ppp dialer dialer pool-member 11 ! !
... and an output from "dsl int atm 1/0" (best shown with fixed character set):
---------------------------------------------------------------------------------------------- ATU-R (DS) ATU-C (US) Modem Status: Showtime (DMTDSL_SHOWTIME) DSL Mode: ITU G.992.1 (G.DMT) ITU STD NUM: 0x01 0x1 Vendor ID: 'ALCB' 'ALCB' Vendor Specific: 0x0000 0x0000 Vendor Country: 0x00 0x0F Capacity Used: 100% 88% Noise Margin: 4.0 dB 8.0 dB Output Power: 20.0 dBm 12.0 dBm Attenuation: 44.0 dB 23.0 dB Defect Status: None None Last Fail Code: Error in early non-CRC message or in first CRC-covered message Selftest Result: 0x00 Subfunction: 0x15 Interrupts: 3383 (0 spurious) PHY Access Err: 0 Activations: 100 Init FW: embedded Operation FW: embedded SW Version: 3.8131 FW Version: 0x1A04
Interleave Fast Interleave Fast Speed (kbps): 0 3712 0 448 Reed-Solomon EC: 0 0 0 0 CRC Errors: 0 64 0 0 Header Errors: 0 16 1 0 Bit Errors: 0 0 BER Valid sec: 0 0 BER Invalid sec: 0 0
------------------------------------------------------------------------------------------------------------------ Thank you in advance,
HD