Cisco 877w soho router - ADSL interface support...

Unanswered Question
Dec 15th, 2009

Hi,

I'm looking to upgrade my current ADSL line to ADLS2/2+ and would like a device that can support all three ADSL functionality if possible (more for ease of migration from the older ADSL to ADSL2/2+....)

I have been reviewing the Cisco 877W {Cisco877W-G-A-M-K9} and it is unclear (to me) if the ADSL port can support the standard ADSL port in addition to the ADSL2/2+ functionality. The following snippets from the "Cisco 870 Series product guide" adds to my confusion:

http://www.cisco.com/en/US/prod/collateral/routers/ps380/ps6200/product_data_sheet0900aecd8028a976.html

Under the "Hardware Specifications - WAN", seems to imply that only ADSL2/2+ is supported on the 87x platforms:

* 871: 100 MB Ethernet  

* 876: ADSL over ISDN (ADSL2/ADSL2+ 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", implies that it can support all 3 x ADSLs:

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+)

*Supports ADSL over basic telephone service with Annex M (except UK Mask) (extended upstream bandwidth)

G.992.3 (ADSL2) and G.992.5 (ADSL2+)

*G.994.1 ITU G.hs

*Support for Reach-extended ADSL2 (G.922.3) Annex L

Complies with T1.413 ANSI ADSL DMT issue 2

*DSL Forum TR-067

*The chipset does not provide interoperability with carrierless amplitude modulation/phase modulation (CAP)-based

ADSL line

*Annex A and Annex B are supported starting with Cisco IOS Software Release 12.4(4)T.

*Annex M (except UK Mask) is supported starting with the special Cisco IOS Software Release 12.4(11)XJ; and

requires the CISCO877-M-K9 or CISCO877W-G-E-M-K9 SKU.

*The ADSL2 standard (ITU G.992.3) adds new features and functions targeted at improving ADSL performance and

interoperability. In addition, the standard adds support for new applications, services, and deployment scenarios.

Among the changes are improvements in data rate and reach performance, rate adaptation, improved diagnostics,

and power enhancements. The conventional ADSL standard (ITU G.992.1) provides downstream data rates of up to

8 Mbps and upstream data rates of up to 0.8 Mbps, and ADSL2 provides higher downstream rates of up to 12 Mbps

and upstream data rates of up to 1 Mbps.

*The ADSL2+ standard (ITU G.992.5) doubles the bandwidth used for downstream data transmission, effectively

doubling the maximum downstream data rates, and achieving downstream data rates of up to 24 Mbps and

upstream data rates of up to 1.5 Mbps.

*Cisco 877-M supports ITU G.992.3 Annex M (except UK Mask), and is optimized for PSD Mask EU-64 M9. Annex M

adds capabilities for extended upstream bandwidth above 2.0Mbps. This allows carriers and enterprises to cover

applications traditionally served by T1, E1, G.SHDSL without overhauling the transport infrastructure. Exact data

rates vary depending on the distance from the DSL access multiplexer (DSLAM), DSLAM type, line card and

chipset, and firmware, noise profile, quality of copper, etc. The reach-extended ADSL2 standard (G.992.3)

So does the 877W support:

1) ADSL / ADSL2 /ADSL2+ ???

2) Annex A and Annex M   ???

Any input would be greater appreciated.

Thanks

Cheers

Andrew

I have this problem too.
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Giuseppe Larosa Wed, 12/16/2009 - 00:42

Hello Andrew,

unless you are in UK you should be fine.

1) 877 should be able to support ADSL2+ and so also ADSL because ADSL2+ is backward compatible

2) 877 M for Annex M as per documentation you have linked

Annex M (except UK Mask) is supported starting with the special Cisco IOS Software Release 12.4(11)XJ; and

requires the CISCO877-M-K9 or CISCO877W-G-E-M-K9 SKU.

Hope to help

Giuseppe

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