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cramer
Premium
join:2007-04-10
Raleigh, NC
kudos:8
reply to swintec

Re: How to lease SB6141?

I found a single reference about a SB6120 and some Dlink with a few seconds of googling. Not that he'd believe anything off the internet.



DrDrew
That others may surf
Premium
join:2009-01-28
SoCal
kudos:15

4 edits

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It wasn't a modem firmware update that caused the problem. It was a CMTS software update to meet updated DOCSIS 3 specs that wasn't compatible with older 6120 firmware, specifically version 1.0.1.8.

The bigger problem was Motorola was still distributing version 1.0.1.8 in it's retail modems several months after the problem came to light (1.0.1.8 was over a year old at that point, the new firmware release on retail after Moto acknowledged the problem was 1.0.3.3). The 1.0.1.8 modems wouldn't sync on CMTSs with the newer software, but the modems weren't bricked. TWC or the other cable companies couldn't update them normally since they wouldn't sync. TWC had updated the 6120 modems on their network before the CMTS update. I'd guess this is why TWC doesn't officially support new customer owned 6120s on their network, since there are still ones with 1.0.1.8 new in the box wandering around. 6121s had newer firmware from the start.

This hit all the MSOs: Charter, Comcast, Cox, BrightHouse, Optimum, and TWC all had threads about the issue here on DSLR:
»[Connectivity] Motorola SB6120 doesn't work with CC-Resolved
»[AZ] SB6120 Provisioning
Many mistakenly thought it was a ISP modem firmware update failure since Motorola never said anything about it publicly. ISPs just had to deal with the fallout and old stock of 6120s ever since. Even Karl misreported it: »Firmware Update Cripples Some Motorola SB6120 DOC 3 Modems

If anything, TWC learned to update customer owned modem firmware more often. As far as I know TWC does update customer modem firmware, when they update other modems of the same make and model. It's can't be requested from customer support, they can't do it, most don't even know how it's done so you get a bunch of odd and wrong answers about it. Modem firmware updates are pushed by an automated process initiated/scheduled by TWCs Engineers.

BTW, the majority of 6120 modems I've seen in my area on TWC are running firmware 1.0.6.3. Retail modems never shipped with that. It was released Aug 2011 by Moto and mid last year by TWC. Motorola has averaged a new firmware for the 6120 every 2-3 months for almost 4 years now, most ISPs are 3-6 months behind at best and none I've seen push every release. The latest I've seen is 1.0.6.10 released Dec 2012.
--
Two is one, one is none. If it's important, back it up... twice. Even 99.999% availability isn't enough sometimes.


bluepoint

join:2001-03-24

1 edit

Good info DrDrew See Profile, thanks.

If anything, TWC learned to update customer owned modem firmware more often. As far as I know TWC does update customer modem firmware, when they update other modems of the same make and model.


cramer
Premium
join:2007-04-10
Raleigh, NC
kudos:8
reply to DrDrew

Am I the only engineer who read that tech note and thought, "well that's easy enough to fix." (not having used an Arris CMTS, I don't know how hard it is to remove that attr from it's response.) After all, why send a D3 attr to a D2 modem? (TWC's database does know what your modem is. myservices/myaccount shows the correct modem for my accounts.)



DrDrew
That others may surf
Premium
join:2009-01-28
SoCal
kudos:15

3 edits

said by cramer:

Am I the only engineer who read that tech note and thought, "well that's easy enough to fix." (not having used an Arris CMTS, I don't know how hard it is to remove that attr from it's response.) After all, why send a D3 attr to a D2 modem? (TWC's database does know what your modem is. myservices/myaccount shows the correct modem for my accounts.)

Huh? The 6120 is a D3 modem.

I also don't think that TLV option is particular to D3, if I remember correctly it's a parameter used in "PowerBoost" configs. The problem was 1.0.1.8 firmware didn't handle that option properly and it was being sent whether or not it was configured on newer CMTS software due to changes in the D3 spec making it default in some way. Firmware before or after didn't have that problem. The vast majority of other modems didn't have an issue with it.

Motorola and their distributors made it worse by selling modems with old firmware for months, even after the problem was found.
--
Two is one, one is none. If it's important, back it up... Somethimes 99.999% availability isn't even good enough.

cramer
Premium
join:2007-04-10
Raleigh, NC
kudos:8

Right. No sleep and no caffeine.

Either way, how hard is it to not send the TLV? On a Cisco, it's usually as easy as "no" in the right place to turn off a default. (maybe not to a specific subset of modems, 'tho)

As for "old stock"... I know first hand how much of a pain in the ass it is to get a new firmware image into the manufacturing processes. (granted, our products are trivial to fix in the field.)



DrDrew
That others may surf
Premium
join:2009-01-28
SoCal
kudos:15

1 edit

said by cramer:

Either way, how hard is it to not send the TLV? On a Cisco, it's usually as easy as "no" in the right place to turn off a default. (maybe not to a specific subset of modems, 'tho)

It's possible, but I think it was made more complicated by the use of PowerBoost.

Some operators using Walled Garden setups changed their default config files for non-provisioned modems in specific ways to allow the modems to sync. That coupled with an automated firmware update system for those specific modems allowed them online. Obviously that meant some extra hoops to jump through for modems already authorized.

So between the failure, time to troubleshoot down to the modem firmware/CMTS software incompatibility, solution testing, and large scale solution deployment, it was several months. All for 1 model modem with 1 specific firmware version which frequently users didn't know had a problem until it was plugged in.

This sort of firmware incompatibility situation happens somewhat frequently with modems, usually not to the point of modems not syncing, but it was made magnitudes worse by the retail distribution of the 6120s and old firmware.
--
Two is one, one is none. If it's important, back it up... Somethimes 99.999% availability isn't even good enough.