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[boost]

Hi!

I look after a few ADSL sites and have noticed that the ones that report an IFTN (0x71C8) DSLAM seem to be generally poor performers (resynchs, CRCs, RCO overcommit, fluctuating SNRs...) This is using STMI based modems, mostly. No doubt, there are a mix of copper issues in there but consistently, it seems to be these that crop up.

I suppose there's a chance I am fighting a losing battle of compatibility so I'm wondering what would be the absolute ideal modem for these sites? I don't need wireless or any fancy features Something that could be bridged back to the existing box would be handy though!

Thanks for any pointers

[burakkucat]

I am using a Huawei HG622 at my end of a circuit from an MSAN which uses an Infineon chipset.

Code: [Select]

# xdslcmd info --vendor   
xdslcmd: ADSL driver and PHY status
Status: Showtime
Retrain Reason: 0
Max: Upstream rate = 1044 Kbps, Downstream rate = 6416 Kbps
Channel: INTR, Upstream rate = 1008 Kbps, Downstream rate = 5595 Kbps

ChipSet Vendor Id: IFTN:0x71c6
ChipSet VersionNumber: 0x71c6
ChipSet SerialNumber:
#

I find either the HG622, the HG610 or the HG612 to be a perfectly stable partner to the above Infineon based MSAN.

As the first two of those Huawei HomeGateways are difficult to source in the UK, I would recommend that you try a HG612 (hint: eBay), updated with Wolfy's latest firmware image. 

[GigabitEthernet]

We're in a nearly identical situation .

What burakkucat said was fair enough, however, Infineon chipset routers provide the fastest sync speeds with Infineon MSANs.

I would recommend a Draytek Vigor 120, but it is a modem only, so you'll need to provide a cable router a long side it. Do your clients already possess cable routers? I couldn't quite deduce that from your post .

TalkTalk's routers have Infineon chipsets in them. Do any of your clients have TalkTalk as their ISP?

[HighBeta]

Mine old ADSL line was a IFTN with around 38 loop loss.

The Netgear DG834GT with its broadcom 6348 chip synced the highest and could run for weeks with a low SNR(3dB) in Fastpath mode.

The Next best came IFTN based 2wire hg2700 (v4 firmware) would also run very stable and cool.
However it didn't like the SNR levels to drop much below 6 other wise it lost sync.

[Blackeagle]

Infineon chipset routers provide the fastest sync speeds with Infineon MSANs.

Mine doesn't !!  It sync's a little lower than the HG612 although interleaving is reduced slightly.  At least, that is the case so far with the (limited) evidence I currently have, although further testing is in the offing 

[roseway]

Infineon chipset routers provide the fastest sync speeds with Infineon MSANs

I can't agree with that as a general statement, although it may be true in some specific cases. I'm on a TT connection, connected to an Infineon MSAN, and Broadcom-based modems give by far the best performance here. It's simply not possible to make that sort of generalisation.

[GigabitEthernet]

Infineon chipset routers provide the fastest sync speeds with Infineon MSANs

I can't agree with that as a general statement, although it may be true in some specific cases. I'm on a TT connection, connected to an Infineon MSAN, and Broadcom-based modems give by far the best performance here. It's simply not possible to make that sort of generalisation.

Can't say I've ever found that. I have contacts on TalkTalk who have identical experiences to me.

However, I do agree that my comment was inaccurate, so I retract that.

[boost]

Thanks for the suggestions! I'll get cracking

Infineon chipset routers provide the fastest sync speeds with Infineon MSANs

I can't agree with that as a general statement, although it may be true in some specific cases. I'm on a TT connection, connected to an Infineon MSAN, and Broadcom-based modems give by far the best performance here. It's simply not possible to make that sort of generalisation.

Performance = throughput? latency? both?

I think I'd take latency and stability over a few extra meg

[roseway]

Performance = throughput? latency? both?

I think I'd take latency and stability over a few extra meg

I'm talking about the combination of speed and stability. Latency isn't important to me, but it's always low here anyway - currently on an interleaved connection, I get ~25 ms to the BBC:

eric@chaffinch:~$ ping bbc.co.uk
PING bbc.co.uk (212.58.244.18) 56(84) bytes of data.
64 bytes from fmt-vip72.telhc.bbc.co.uk (212.58.244.18): icmp_seq=1 ttl=53 time=24.8 ms
64 bytes from fmt-vip72.telhc.bbc.co.uk (212.58.244.18): icmp_seq=2 ttl=53 time=24.9 ms
64 bytes from fmt-vip72.telhc.bbc.co.uk (212.58.244.18): icmp_seq=3 ttl=53 time=24.1 ms
^C
--- bbc.co.uk ping statistics ---
3 packets transmitted, 3 received, 0% packet loss, time 2003ms
rtt min/avg/max/mdev = 24.174/24.667/24.947/0.349 ms
eric@chaffinch:~$

[Chrysalis]

What is RCO overcommit?

[kitz]

What is RCO overcommit?

Relative Capacity Occupation.

The existing sync rate expressed as a percentage against the Maximum Attainable Rate.
For example if you were sync'd at 8128 kbps because of restriction at the dslam or on your account, but the router estimates that your line is capable of 16Mbps, then the RCO would be 50% as you would only be using 50% capacity.

Read more: http://www.kitz.co.uk/adsl/linestats_explanation.htm#ixzz2yLLtxRnG

[Chrysalis]

ahh yeah now it rings a bell, DMT showed RCO on speedtouch modems.

normally would be 99% or so on fast path but reduced when FEC enabled.

[burakkucat]

Around 96% - 97% when interleaved, I believe.