topic Re: SIP WAN DOWN in Broadband

SIP WAN DOWN

LawTurley — Sun, 17 Aug 2025 09:06:53 GMT

I've been having daily dropouts for weeks now, which I've reported multiple times. Every time I go through the same process of testing by Plusnet and then being told it's resolved, only to have the same issue reoccur. I don't know how useful this part of the log will be, but this is when it drops out:

09:36:00, 17 Aug.SIP WAN UP
09:35:57, 17 Aug.SIP WAN DOWN
09:35:57, 17 Aug.NTP synchronization start
09:35:57, 17 Aug.UPnP is enabled
09:35:57, 17 Aug.WAN Sensing Auto sensing Complete, interface selected
09:35:57, 17 Aug.WAN Sensing Auto sensing Running
09:35:57, 17 Aug.Success - secondary DNS servers
09:35:57, 17 Aug.Success - primary DNS servers
09:35:56, 17 Aug.WAN connection WAN2_INTERNET_PTM connected
09:35:56, 17 Aug.PPP: IPCP up

Re: SIP WAN DOWN

LawTurley — Sun, 17 Aug 2025 09:32:08 GMT

I've copy+pasted more of it here:

09:39:44, 17 Aug.
ARP [add] br0(wl0) 192.168.1.152 76:8b:79:22:e4:fb

09:39:40, 17 Aug.
DHCP device Connected: 192.168.1.152, 76:8b:79:22:e4:fb, CMF-by-Nothing-Phone-1

09:39:39, 17 Aug.
DHCP lease issued 192.168.1.152 to 76:8b:79:22:e4:fb CMF-by-Nothing-Phone-1, lease duration is 86400 seconds

09:39:39, 17 Aug.
5G Client associate from 76:8b:79:22:e4:fb (IP=192.168.1.152) RSSI=-70, Rate=390Mbps, host CMF-by-Nothing-Phone-1

09:39:39, 17 Aug.
LAN [ADD] ARP 192.168.1.152 with 76:8b:79:22:e4:fb from br0(wl0)

09:39:39, 17 Aug.
Receive a DHCP request

09:39:39, 17 Aug.
Lan IPv6 Neighbour Discovery events: NEIGHBOR_SOLICIT

09:37:43, 17 Aug.
CWMP: HDM socket closed successfully.

09:37:43, 17 Aug.
CWMP: HTTP authentication success from pbthdm.x.x.x

09:37:43, 17 Aug.
CWMP: HDM socket opened successfully.

09:37:43, 17 Aug.
CWMP: session completed successfully09:36:05, 17 Aug.
PPP IPV6CP Send Configuration Request

09:36:02, 17 Aug.
PPP IPV6CP Send Configuration Request

09:35:59, 17 Aug.
PPP IPV6CP Send Configuration Request

09:35:59, 17 Aug.
SIP WAN UP

09:35:56, 17 Aug.
SIP WAN DOWN

09:35:56, 17 Aug.
NTP synchronization start

09:35:56, 17 Aug.
UPnP is enabled

Re: SIP WAN DOWN

LawTurley — Sun, 17 Aug 2025 09:34:37 GMT

Not sure if you'll agree, but I pasted the whole log into ChatGPT and it says:

The log shows that when SIP WAN DOWN appears, your router really loses its WAN/PPP session, not just SIP. The internet itself is dropping, then reconnecting a few seconds later.

This is consistent with:

A line issue (DSL/cable/fiber link dropping momentarily).
PPP session resets (ISP or router ending the session).
Router firmware bug or reboot (less likely since your log continues without a full restart).

Re: SIP WAN DOWN

jab1 — Sun, 17 Aug 2025 09:42:08 GMT

@LawTurley Not really my area of expertise, but I would suggest your issue is more consistent with the first of those three conditions you quote above. Two and three are unlikely - IMO. Which version of the Hub are you using?

Re: SIP WAN DOWN

LawTurley — Sun, 17 Aug 2025 09:50:38 GMT

Product code: Plusnet Hub Two

Serial number: +108417+2320001742

Firmware version: v0.10.00.04201-PN

This information might also be useful:

DSL uptime:0 Days 1 Hr 10 Mins
Data rate:20 Mbps / 79.999 Mbps
Maximum data rate:34.114 Mbps / 139.366 Mbps
Noise margin:15.0 / 21.5
Line attenuation:3.9 / 7.5

Re: SIP WAN DOWN

Dan_the_Van — Sun, 17 Aug 2025 09:57:38 GMT

@LawTurley

SIP down is associated with VoIP so it can be ignored.

As you have a DSL connection you should be concentrating on DSL Link Down messages.

Re: SIP WAN DOWN

LawTurley — Sun, 17 Aug 2025 10:03:46 GMT

Just before it went down I had:

9:35:55, 17 Aug.

PPP: Received PADS

09:35:55, 17 Aug.

PPP: Sending PADR

09:35:55, 17 Aug.

PPP: Received PADO

09:35:55, 17 Aug.

PPP: Sending PADI

09:35:50, 17 Aug.

PPP: Sending PADI

09:35:45, 17 Aug.

PPP: Sending PADI

09:35:40, 17 Aug.

PPP: Sending PADI

09:35:37, 17 Aug.

DSL Link Up: Down Rate=79999kbps, Up Rate=20000kbps; SNR Margin Down=21.3dB, Up=15.1dB

09:35:35, 17 Aug.

PPP: Sending PADI

09:35:30, 17 Aug.

PPP: Starting PPP daemon

09:35:29, 17 Aug.

WAN Auto-sensing detected port DSL WAN

09:32:14, 17 Aug.

ARP [add] br0(wl0) 192.168.1.230 9a:30:4c:5f:5b:66

Re: SIP WAN DOWN

jab1 — Sun, 17 Aug 2025 10:04:36 GMT

@LawTurley Are you sat inside the FTTC cab? those attenuation figures suggest something a bit 'off' to me. Your DSL uptime and noise margin figures suggest a line fault - to me.

If you can export your full event log and attach the resulting .csv file to a post, maybe we can advise further.

Re: SIP WAN DOWN

MisterW — Sun, 17 Aug 2025 10:06:18 GMT

Data rate:20 Mbps / 79.999 Mbps
Maximum data rate:34.114 Mbps / 139.366 Mbps
Noise margin:15.0 / 21.5

With those stats , particularly the high (good) noise margins, you wouldn't expect many DSL drops UNLESS there's a significant fault on the line.

It might also be useful to check the log for any router restarts or reboots...

Re: SIP WAN DOWN

LawTurley — Sun, 17 Aug 2025 10:08:01 GMT

We are literally about 20m from the cab, yes.

Re: SIP WAN DOWN

jab1 — Sun, 17 Aug 2025 10:09:35 GMT

@MisterW Those attenuation figures look suspiciously low to me, or am I misreading something?

Re: SIP WAN DOWN

LawTurley — Sun, 17 Aug 2025 10:13:37 GMT

@jab1 wrote:

@LawTurley Are you sat inside the FTTC cab? those attenuation figures suggest something a bit 'off' to me. Your DSL uptime and noise margin figures suggest a line fault - to me.

If you can export your full event log and attach the resulting .csv file to a post, maybe we can advise further.

I have no idea how to do that other than to copy+paste page by page, the router doesn't seem to have the option to view the whole log, only page by page?

Re: SIP WAN DOWN

jab1 — Sun, 17 Aug 2025 10:19:47 GMT

Navigate to Home>Advanced settings>Technical Log in the router, and you should see the option to 'export' towards the top RHS, as in the screenshot below:

Re: SIP WAN DOWN

LawTurley — Sun, 17 Aug 2025 10:22:55 GMT

@jab1 wrote:

Navigate to Home>Advanced settings>Technical Log in the router, and you should see the option to 'export' towards the top RHS, as in the screenshot below:

Gah! Right in front of me! OK, here is the csv.

Re: SIP WAN DOWN

jab1 — Sun, 17 Aug 2025 10:32:01 GMT

I can't see the expected DSL drops on there, although I note a couple of 'BOOT' entries which suggest, unless you are intentionally totally shutting the Hub down, that you have a dodgy Hub.

I'm not going to be sat in front of the laptop much this morning - maybe @Dan_the_Van or @MisterW may have some thoughts?

Re: SIP WAN DOWN

MisterW — Sun, 17 Aug 2025 10:42:56 GMT

I'd concur with @jab1 here, there's certainly not the expected number of DSL 'down' events , although I did find one.

There are a considerable number of router restarts ( power button ) including one on the 13 Aug around 06:30 where it restarted 4 times before sucessfully restarting!

Unless @LawTurley is really restarting the router manually ? or something is knocking the router power switch ?

@LawTurley check that the power plug is fully seated in the router

Are you able to try a different mains socket ?

Re: SIP WAN DOWN

jab1 — Sun, 17 Aug 2025 10:49:35 GMT

@MisterW Yep, saw the 'DSL down' this morning, but there are a total of (IIRC) 382 over the whole log.

Re: SIP WAN DOWN

LawTurley — Sun, 17 Aug 2025 10:57:19 GMT

@jab1 wrote:

I can't see the expected DSL drops on there, although I note a couple of 'BOOT' entries which suggest, unless you are intentionally totally shutting the Hub down, that you have a dodgy Hub.

I'm not going to be sat in front of the laptop much this morning - maybe @Dan_the_Van or @MisterW may have some thoughts?

We've had a couple of power cuts down here lately, I'm thinking that's probably what that is.

Re: SIP WAN DOWN

Baldrick1 — Sun, 17 Aug 2025 11:48:51 GMT

I’m a bit surprised that repeated power drop out or even brown out events do not trigger a hub reboot, My money would be on a faulty hub.

Re: SIP WAN DOWN

MisterW — Sun, 17 Aug 2025 12:33:25 GMT

Searched through that log for 'ERROR_NO_CARRIER' which is what you'd generally see as WAN disconnection reason as a result of a DSL drop. This occurred once on Aug 14 , the previous one being in Nov last year !! There were two in that Nov and two in Sept .

There are however lots of DSL Up: events , preceded by a hub restart due to a power on.

@LawTurley unless you are getting lots of power cuts , I suspect you have a faulty hub