Kitz ADSL Broadband Information
adsl spacer  
Support this site
Home Broadband ISPs Tech Routers Wiki Forum
 
     
   Compare ISP   Rate your ISP
   Glossary   Glossary
 
Please login or register.

Login with username, password and session length
Advanced search  

News:

Pages: 1 [2] 3

Author Topic: Availability of L2 Retx (proprietary PhyR or standard G.INP) on upstream?  (Read 2758 times)

ejs

  • Kitizen
  • ****
  • Posts: 2038

PhyR and G.INP are not the same though.

I assume that the capability for upstream PhyR is enabled on Weaver's modems. The Openreach HG612 has PhyR enabled on the downstream but disabled on the upstream by default, so perhaps other Broadcom modems have similar PhyR default settings.
Logged

kitz

  • Administrator
  • Senior Kitizen
  • *
  • Posts: 32444
  • Trinity: Most guys do.
    • http://www.kitz.co.uk

Agreed.... but PhyR was the basis for G.998.4

Quote
Broadcom's PhyR impulse noise protection and retransmission technology is currently being considered for DSL standardization.

I can't find any other SP who has used retransmission with adsl2/2+ that enabled it on the upstream.   

The question was availability of upstream Retx being available for Weavers line.   That answer would be no because he's on adsl2/2+.


Logged
Please do not PM me with queries for broadband help as I may not be able to respond.
-----
How to get your router line stats :: ADSL Exchange Checker

ejs

  • Kitizen
  • ****
  • Posts: 2038

Apparently G.998.4 was the amalgamation of two different vendor retransmission schemes (according to the Ikanos pdf here). The absence of upstream retransmission for ADSL2/2+ in G.998.4 could be from limitations of one scheme, or the other, or how they were combined, or some other reason.

Because PhyR is not G.998.4, the non-existence of G.998.4 for ADSL2/2+ upstream does not imply the non-existence of PhyR for the ADSL2/2+ upstream.
Logged

Weaver

  • Addicted Kitizen
  • *****
  • Posts: 8672
  • Retd sw dev; A&A; 4 × 7km ADSL2; IPv6; Firebrick

The stats give the impression that Broadcom or ZyXEL’s designers were expecting upstream PhyR to be a possibility, because they show stats relating to PhyR for upstream, which are all zero of course.
Logged

ejs

  • Kitizen
  • ****
  • Posts: 2038

Is upstream PhyR enabled on your modems? You can check with: xdslctl profile --show
Logged

Weaver

  • Addicted Kitizen
  • *****
  • Posts: 8672
  • Retd sw dev; A&A; 4 × 7km ADSL2; IPv6; Firebrick

As expected, enabled by the look of it ?

Code: [Select]
VMG1312-B10A
Login: admin
Password:
 > xdslctl profile --show

Modulations:
        G.Dmt   Disabled
        G.lite  Disabled
        T1.413  Disabled
        ADSL2   Enabled
        AnnexL  Enabled
        ADSL2+  Disabled
        AnnexM  Disabled
        VDSL2   Disabled
Phone line pair:
        Inner pair
Capability:
        bitswap         On
        sra             On
        trellis         On
        sesdrop         Off
        CoMinMgn        Off
        24k             Off
        phyReXmt(Us/Ds) On/On
        TpsTc           AvPvAa
        monitorTone:    On
        dynamicD:       On
        dynamicF:       On
        SOS:            On
        Training Margin(Q4 in dB):      -1(DEFAULT)
 >
Logged

ejs

  • Kitizen
  • ****
  • Posts: 2038

Yes it's enabled in both directions.

I don't think 24k bytes of interleaving memory needs to be disabled, although I think that's only applicable to ADSL2+ (where modems can use either 16k or 24k bytes of interleaving memory).
Logged

burakkucat

  • Global Moderator
  • Senior Kitizen
  • *
  • Posts: 29432
  • Over the Rainbow Bridge
    • The ELRepo Project

That is an interesting comment regarding the 24k bytes of interleaving memory. I've just taken a look at the configuration of my VMG1312-B10A and see that the 24k capability is "on".

> xdslctl profile --show

Modulations:
   G.Dmt   Disabled
   G.lite  Disabled
   T1.413  Disabled
   ADSL2   Enabled
   AnnexL  Disabled
   ADSL2+  Disabled
   AnnexM  Disabled
   VDSL2   Enabled
VDSL2 profiles:
   8a      Disabled
   8b      Disabled
   8c      Disabled
   8d      Disabled
   12a     Disabled
   12b     Disabled
   17a     Enabled
   30a     Disabled
   US0     Disabled
Phone line pair:
   Inner pair
Capability:
   bitswap      On
   sra          On
   trellis      On
   sesdrop      Off
   CoMinMgn     Off
   24k          On
   phyReXmt(Us/Ds)   On/On
   TpsTc        AvPvAa
   monitorTone: On
   dynamicD:    On
   dynamicF:    On
   SOS:         On
   Training Margin(Q4 in dB):   -1(DEFAULT)
 >
Logged
:cat:  100% Linux and, previously, Unix. Co-founder of the ELRepo Project.

Please consider making a donation to support the running of this site.

Weaver

  • Addicted Kitizen
  • *****
  • Posts: 8672
  • Retd sw dev; A&A; 4 × 7km ADSL2; IPv6; Firebrick

I don’t understand that 24k entry. It isn’t something that I have every seen in the UI anywhere, so it isn’t a choice that I made intentionally when configuring the thing.

Is there a chance that that option, however it has got set the way it has, is restricting the device’s ability to choose the highest interleave depths ?


I could do with some help understanding the other entries in that list, but that topic deserves a thread in its own.
« Last Edit: April 04, 2019, 02:58:43 AM by Weaver »
Logged

burakkucat

  • Global Moderator
  • Senior Kitizen
  • *
  • Posts: 29432
  • Over the Rainbow Bridge
    • The ELRepo Project

The only comment I can make is that my device was configured entirely from the GUI and not by editing a pre-saved configuration file which was then subsequently restored.
Logged
:cat:  100% Linux and, previously, Unix. Co-founder of the ELRepo Project.

Please consider making a donation to support the running of this site.

ejs

  • Kitizen
  • ****
  • Posts: 2038

The 24k option is only applicable to ADSL2+.

ADSL2 only has 16002 bytes available for interleaving. Opting for ADSL2 only removes the possibility of using 24000 bytes for interleaving.
Logged

Weaver

  • Addicted Kitizen
  • *****
  • Posts: 8672
  • Retd sw dev; A&A; 4 × 7km ADSL2; IPv6; Firebrick

I robotically edited the config file by using a program that applies regex-based search-replace operations on the XML to change things like IPv4 addresses per modem, and n-th modem index numbers 1,2,3,4 where needed to make them correct per-modem, that kind of thing. I then checked the output by diff-ing the output against the original, so as to make sure that the program had not only done the right thing where it was supposed to but had also not gone ‘rogue’ and applied any changes anywhere else where it shouldn’t due to a false accidental match. The edit operations used complex ‘context’ regexes to strictly limit edit sites down to where they are supposed be, only in the right XML context. So I was quite paranoid about the likelihood of bugs.

The modems refer to per-modem addresses 192.168.n.1 and 192.168.n.254, where n is 1…4, and .n.1 is the modem’s admin interface looking towards the Firebrick and .n.254 is the Firebrick’s modem-facing interface. That is one example of a systematic change that is straightforward.
Logged

burakkucat

  • Global Moderator
  • Senior Kitizen
  • *
  • Posts: 29432
  • Over the Rainbow Bridge
    • The ELRepo Project

The 24k option is only applicable to ADSL2+.

ADSL2 only has 16002 bytes available for interleaving. Opting for ADSL2 only removes the possibility of using 24000 bytes for interleaving.

That is another interesting fact I have just learned.

The service I receive is deployed from the TalkTalk MSAN in ADSL2+ (ITU-T G.992.5) mode. I restrict the circuit to operate in ADSL2 (ITU-T G.992.3) mode by appropriate configuration of the CPE. Hence the former, I presume, is why the 24k option is seen enabled within my VMG1312-B10A.

However that has me slightly puzzled by what we now know about the four services deployed from the Broadford exchange to the Heasta "Weaving Shed".  :-\
Logged
:cat:  100% Linux and, previously, Unix. Co-founder of the ELRepo Project.

Please consider making a donation to support the running of this site.

Weaver

  • Addicted Kitizen
  • *****
  • Posts: 8672
  • Retd sw dev; A&A; 4 × 7km ADSL2; IPv6; Firebrick

The 24k option means 24k * 1k = 24 Mbps? = G.992.5?
Logged

burakkucat

  • Global Moderator
  • Senior Kitizen
  • *
  • Posts: 29432
  • Over the Rainbow Bridge
    • The ELRepo Project

The 24k option means 24k * 1k = 24 Mbps? = G.992.5?

Looking at the words of our own expert, earlier, above --

I don't think 24k bytes of interleaving memory needs to be disabled, although I think that's only applicable to ADSL2+ (where modems can use either 16k or 24k bytes of interleaving memory).

-- I think you have misinterpreted the meaning of that option!
Logged
:cat:  100% Linux and, previously, Unix. Co-founder of the ELRepo Project.

Please consider making a donation to support the running of this site.
Pages: 1 [2] 3
 

anything