Fastpath & Interleaving status

[Corphish]

Hello, all!

I'm new to OpenWrt, have just flashed it to my TP-Link W8980. I just have a couple of questions.

1. Is there any router or specific firmware able to force fastpath? or that is only controlled by ISP?

2. How can I tell if I'm on a fast or interleaved channel through OpenWrt? and where to find interleaved depth and delay values?

Thanks.

[Sunspark]

1. None, this isn't even an ISP level setting, it's a telco setting. The ISP can request that it be turned on and if your line quality signal is good enough, they can.
2. You can't, log into the modem you're using and review the line stats there. I have VDSL, on mine it shows: D (interleaver depth): 1 on VDSL it means that while it is on interleaved, a depth of 1 is functionally equivalent to fast-path.

[moeller0]

@Corphish

1. How can I tell if I'm on a fast or interleaved channel through OpenWrt? and where to find interleaved depth and delay values?

Ssh into the modem and run the following command:
/etc/init.d/dsl_control status
which should give you a bit of information, including about the interleaving.

Also run mtr -ezb4w -c 100 8.8.8.8 or similar to get an idea about the RTT to the next hop (which is typically not your DSLAM) combined interleaving delay for up- and downstream needs to be smaller than the RTT to the next upstream hop.

[Corphish]

@Sunspark

You can't, log into the modem you're using and review the line stats there. I have VDSL, on mine it shows: D (interleaver depth): 1 on VDSL it means that while it is on interleaved, a depth of 1 is functionally equivalent to fast-path.

@moeller0

Ssh into the modem and run the following command:
/etc/init.d/dsl_control status
which should give you a bit of information, including about the interleaving.

Thanks guys! Unfortunately, I can't find interleave depth value anywhere, only Latency [Interleave delay] : 8ms/3ms
Now since delay > 0 does that necessarily imply that I'm on the interleaved channel? Anyway to get that depth value?

@moeller0

Also run mtr -ezb4w -c 100 8.8.8.8 or similar to get an idea about the RTT to the next hop (which is typically not your DSLAM) combined interleaving delay for up- and downstream needs to be smaller than the RTT to the next upstream hop.

When I enter this line, it returns this "-ash: mtr: not found". May you please give further explanation on this?

[moeller0]

Ah, in that case mtr is not installed, do opkg update ; opkg install mtr .

[Sunspark]

Too much trouble. Just go to the unit's internal webpage instead.
Device Info>Statistics>xDSL

[Corphish]

That's what I was after, these commands retrieve some additional information about interleaving including interleave depth, interleave block, and the channel type...

dsl_cpe_pipe.sh g997fpsg 0 1 | this should be the download direction
dsl_cpe_pipe.sh g997fpsg 0 0 | upload direction

here's the output

nReturn=0 nChannel=0 nDirection=1 nNFEC=32 nRFEC=16 nLSYMB=16 nINTLVDEPTH=1 nINTLVBLOCK=32 nLPATH=0

I've also found that this command dsl_cpe_pipe.sh g997csg returns some information about INP

ActualImpulseNoiseProtection=370
ActualImpulseNoiseProtectionRein=0
ActualImpulseNoiseProtectionNoErasure=40

Any idea what are the differences between these three values? or which one is corresponding to the value showed by my ISP modem?

Unfortunately, I don't have that modem so I can compare the values.