dslreports logo
 
    All Forums Hot Topics Gallery
spc
Search similar:


uniqs
2044

soadlink
join:2002-11-17
USA

soadlink

Member

P-663H-51 gets public IP, but barely any connectivity

I bought the ZyXEL P-663H-51 to replace my Cisco DDR2200 modem (that has issues of its own) because it's the only modem I can find that supports the bonded DSL standard (ITU 998.1).

It arrived today and I plugged it in, and right off the bat it syncs up the 2 dsl pairs just fine and shows roughly 25Mbps/2Mbps (two 12.5/1 dsl lines) which is the package that I pay for through CenturyLink. After changing to PPPoE, entering my credentials, and rebooting... the modem comes back up just fine with a public IP address!

All fine and dandy, except the connection is horribly horribly slow... it almost isn't even there. I can't even load a web page. However, if I do a traceroute or a ping out to the internet I can get lucky and MIGHT get a response maybe once every 10 seconds. But it is getting a public address and syncing ok, and the lights stay SOLID green the entire time. It just feels like there is absolutely no connection at all.

I am a very technical person, and have been trying everything I can think of:
- Upgrading/downgrading the firmware to all available versions on ZyXELs website
- Putting the modem in bridged mode and letting the PC handle the PPPoE session
- Duplicating the EXACT settings from the old DDR2200 modem (VPI/VCI 8/35...ubr without pcr, etc.etc.. anything I can find)
- Tweaking and turn on/off all settings that might help

And so on, and so forth... nothing seems to work!

What's interesting is that when I plug in the old DDR2200 it works just fine. So I'm almost thinking there is something up with the ZyXEL modem (maybe a setting), or my ISP has a special setup that isn't allowing this modem (I doubt it, but I don't know the ISP side of the technology that well). Now you might say "then just use your DDR2200"... well there's a whole other long story of why I don't want to use it... it has issues of its own which is why I decided to try the ZyXEL.

Anyways, I'm hoping someone out there has heard of this issue and knows of a fix. Or maybe there is something I can double check. I have emailed ZyXEL support with pretty much all the info above so I will see what they say as well.

Thanks for reading!

leibold
MVM
join:2002-07-09
Sunnyvale, CA
Netgear CG3000DCR
ZyXEL P-663HN-51

leibold

MVM

What do the varies device status and statistics pages show when you login to the P-663H-51 ?

There isn't anything that immediately comes to mind to explain the behavior you are seeing. Have you tried to connect only one DSL line to see if it is a bonding issue ? The P-663HN-51 is working fine when only one line (either one) is active and the same should be true for the P-663H-51 (apart from the wireless-N they are similar products).

soadlink
join:2002-11-17
USA

soadlink

Member

Here is a picture of the various pages and their stats: »i.imgur.com/DHVMi.png

The phone jack is wired for 2 pairs, and the cable from the wall to the modem is an RJ-11 phone cord with 2 pairs crimped in (4 total wires in 1 cable). So to test your theory I just un-screwed the plate and tried disconnecting each pair from the back of it. The modem shows 1/2 the speed which is normal, but I can't seem to establish the PPPoE session with just 1 of pairs. After both pairs are connected, I can establish a PPPoE session.

I remember talking to the head DSL guy in my town a few months back and he said that the 2 pairs are bonded in the switch down the street as well, and that if you are trying to connect from nothing with only 1 pair it won't work. He said the redundancy is only there when the connection is already established and you lose 1 pair you will continue to stay connected on that 1 pair at half speed until you reboot your modem. At that point you're screwed, unless you manage to get both pairs back. This seems to be true on both the DDR2200 and the ZyXEL.

No word from ZyXEL support yet. My family also has the 25Mbps package at their house so I'm going to try the modem there.

ZyXELs website said the modem is CALIX certified which is the brand of the switch down the street. Not sure if it makes a big difference but it was kind of a selling point for me.

leibold
MVM
join:2002-07-09
Sunnyvale, CA
Netgear CG3000DCR
ZyXEL P-663HN-51

leibold

MVM

Your ISP is clearly doing things differently then mine (Sonic.net). Sonic doesn't use PPPoE and doesn't have speed tiers (service is as fast as the line can handle).

I have the ZyXEL P-663HN-51 and the Comtrend Nexuslink 5631 and both will continue to work if one of the two lines goes down. However a single-line dsl modem will not work on one line of a bonded pair because even with a single working line the G.998.1 bonding feature must be supported by the modem (perhaps that is what your head DSL guy meant ?).

G.998.1 bonding takes place at the ATM level and should be completely transparent to any IP traffic above it. The protocol specifically supports dynamic adding and removing DSL lines to/from service without manual intervention (the standard supports bonding of up to 32 lines, but actual modems only support 2).

When I switched to Sonic Fusion (bonded DSL) the modem synced and was online as soon as one of the pairs was hooked up to the DSLAM and I was able to access the Internet before the second pair was connected (a few minutes later). At least with Sonic the redundancy of two lines works not only if you loose an already established line but also when starting the modem with only one line connected.

Trying your modem at another location is a good idea to see if yours is defective, but before you do that you may want to set the default gateway on the DHCP server (for the LAN side of the DSL modem) to 192.168.1.1. Without that default gateway being announced your PC will be able to access the DSL modem, but won't know where to send packets to the Internet. Your picture shows the default gateway address as blank.

soadlink
join:2002-11-17
USA

soadlink

Member

Thanks for the info! I think the default gateway is missing in those pictures because the modem didn't have a PPPoE session there (since it's in bridged mode in those pics). The pc had the actual PPPoE session going.

I remember the DSL guy saying the technology is supposed to be exactly like you said: 1 pair and you're good no matter what. But he said they were doing it a little differently (for whatever reason) so it wouldn't work for me exactly like that. Maybe that's why this modem is so flakey is because of their non-standard setup. But the ZyXEL seems to use the same chipset (broadcom) as the DDR2200... and the interface and options are very similar. It looks like each vendor took a base config and tweaked it the way they wanted it... but underneath the hardware is the same or very similar.

So far I've seen the following modems support G.998.1: P-663H-51, P-663HN-51, Comtrend Nexuslink 5631, DDR2200. I'd like to try them all, but they aren't cheap. I bought this one knowing I could return it if it didn't work.

The reason I'm doing all this is because at my house... and my parents house... if I max the download for a long time, the DDR2200 does a hard lockup and has to be rebooted. It happens quicker at my house, but the same issue happens at both houses, and they are pretty far apart. Same town, but still far apart. After 2-3 months of trying things now (swapping cards, swapping lines, replacing modems, etc) the phone company is still unsure as to what the problem is. I am almost convinced it's the modem as I can't even get in to it or ping it when the DSL does down. It's gotta be a hard lockup at the modem.

Ah well, I will do more testing at my parents house and see what I come up with. If it's the same issue I'll RMA the modem for another one just to be sure it's not faulty. And if the same issue happens I'll get a refund and probably just wait for VDSL which is 1-2 months away in my area

leibold
MVM
join:2002-07-09
Sunnyvale, CA
Netgear CG3000DCR
ZyXEL P-663HN-51

leibold

MVM

said by soadlink:

So far I've seen the following modems support G.998.1: P-663H-51, P-663HN-51, Comtrend Nexuslink 5631, DDR2200. I'd like to try them all, but they aren't cheap. I bought this one knowing I could return it if it didn't work.

I don't know the DDR2200 at all and only know the P-663H-51 from the documentation and pictures of the inside. The Comtrend and the ZyXEL use the same broadcom chipsets (two of the same single-line all-in-one dsl modem chipset). Apart from the wireless radios the differences between them are minor.

soadlink
join:2002-11-17
USA

soadlink

Member

Well same exact issue at my parents' house.

I am gonna go with my hunch that a replacement ZyXEL modem would do the same thing, and just get a refund for the modem to save time. VDSL beta testing is right around the corner and the DSL guy at the phone company said Im going to be the first customer in town to be a beta tester for it. I can wait about 1 month for that.
soadlink

soadlink to leibold

Member

to leibold
Sorry to bump an old topic, but I resolved this issue. I ended up returning the modem and purchasing the wireless model (P-663HN-51).

It had the exact same issue, but I have gained a bit of knowledge on my ISPs setup through troubleshooting since my last post. Long story short I disabled QoS in a few places where it showed enabled. I also disabled Fullcone NAT and Firewall under the WAN interface. Lastly, I checked the box for AnnexM as it was unchecked. After a reboot the modem is online and I am getting my full speeds without any issues!

leibold
MVM
join:2002-07-09
Sunnyvale, CA
Netgear CG3000DCR
ZyXEL P-663HN-51

leibold

MVM

Thanks for the update. I don't do NAT in the DSL modem since I have static IP addresses (the modem is in bridge mode).
said by soadlink:

Lastly, I checked the box for AnnexM as it was unchecked.

I'm also using AnnexM since I run some Internet servers from home You should know that turning on AnnexM (if it is also turned on at the ISP side) will reduce your download speed but improve your upload speed (not necessarily at the same rate).