configure annex b on cisco 877

Unanswered Question


I run into problem.I need to configure annex B on cisco 877 SOHO router.

I found that 877 can operate on annex B

* 877: ADSL over analog telephone lines (ADSL2/ADSL2+ Annex A and Annex M (except UK Mask))

* 878: G.SHDSL (2- and 4-wire support)

* 3 Mbps IMIX aggregate performance for Cisco 878

Yet, further down under the  in the "Hardware Specifications - DSL Specifications"

DSL Specification:

* ST-Microelectronics 20190 Chipset

* Supports ADSL over basic telephone service with Annex A and Annex B ITU G. 992.1 (ADSL), G.992.3 (ADSL2),

and G.992.5 (ADSL2+)

When I choose dsl operating-mode under interface atm 0 i have only:

adsl2     ITU G.992.3 Annex A and L
  adsl2+    ITU G.992.5 Annex A
  ansi-dmt  ANSI T1.413
  auto      auto detect mode
  itu-dmt   ITU G.992.1 Annex A

I'm using IOS c870-advsecurityk9-mz.124-24.T2.bin.

Please help!!!


  • 1
  • 2
  • 3
  • 4
  • 5
Overall Rating: 0 (0 ratings)
paolo bevilacqua Tue, 03/02/2010 - 13:44
User Badges:
  • Super Gold, 25000 points or more
  • Hall of Fame,

    Founding Member

The 877 does NOT support Annex B (ADSL over ISDN)

Only the 876 does.

Check table 1.

Before you ask again, there is NO configuration, modification, or other technique to make an 877 connect ADSL Annex B.

Foximaxi1 Thu, 03/04/2010 - 06:44
User Badges:

It is interesting, because the hardware is the same (ST20190). May be that the IOS decide it, when it checks the FRU number. 1 bit different.

I have the same problem in Hungary, I have checked very accurately what type of router to buy, but my ISP uses Annex B on Analog line!!!!

The final solution, to sell it, or use with a modem and an "advipservices" feature set IOS to route to another FE port.

paolo bevilacqua Fri, 03/05/2010 - 04:11
User Badges:
  • Super Gold, 25000 points or more
  • Hall of Fame,

    Founding Member

The chipset is the same but in electrical terms BRI is very different from analog. For one, there is no ring current on BRI.

Consequently, line termination circuits must be different on CPE.


This Discussion

Related Content