Why is router mode needed for diagnostics to be run?

[IPFreely]

I've seen a few posts from the team informing they can't run tests until the Hub is put into router mode. I'm bemused by this. All cable modems when they come online pull an IP address for themselves so that they can be managed. This is completely independent of the public IP address that the customer's equipment or, in router mode, the Hub itself, may pull.

The only two possibilities that come to mind are either a conscious decision on the part of VM or Liberty Global to configure things in such a way that router mode is required or that there's a major software issue with the Hubs.

Something that comes to mind is Liberty insisting on hosting the diagnostics in Schipol or wherever and not being able to reach the cable side IP addresses on VM's network as there's no IPv6 there yet, so they're reaching from the public IP in the Hub's router mode.

[jb66]

I would imagine the software required to monitor your connection is only active when in router mode

[IPFreely]

There is no extra software required. Can pull upstream data from the CMTS, downstream data from the cable modem via SNMP.

[Adduxi]

I believe the Samknows client is imbedded in the firmware and is only accessible in Router mode?

[IPFreely]

Okay. Required to run a speed test. That's fine: how about basic checks?

[g0akc]

I suspect it’s because there won’t be full CWMP (TR69) functionality to the VM ACS in modem mode.

Certain ports won’t be available.

there won’t be details of lan side devices, radios and so on obviously.

interesting blog Here 

[legacy1]

Yes I too don't get it I think VM just say please put hub in router mode for checks because they know no better as to the extra tests that may not help with your connection and that they really get all the info they need with hub in modem mode anyway. As for speed test maybe but they could stick a 10. server for speed test I'm guessing modem mode pulls a 10. with gateway IP that could route to a 10. speed test server or they could SNAT 10. IPs out a WAN gateway

[IPFreely]

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@g0akc wrote:

I suspect it’s because there won’t be full CWMP (TR69) functionality to the VM ACS in modem mode.

Certain ports won’t be available.

there won’t be details of lan side devices, radios and so on obviously.

interesting blog Here 

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Don't need TR69 to check upstream and downstream power levels, SNR, error rates, etc and I've never heard of TR69 being used on cable. There could actually be any ports VM want available in modem mode: cable modems have full IP access on their management plane: cable modems pull an IP address for themselves from a DHCP server as part of coming online and have a full IP stack listening on the cable side. It's bridge mode not a modem so anything goes as long as anything not addressed to the modem is passed to the LAN.

[g0akc · Accepted solution]

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@IPFreely wrote:

Don't need TR69 to check upstream and downstream power levels, SNR, error rates, etc and I've never heard of TR69 being used on cable. 

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If you look online there are many references to VM using TR069 to manage their CPE. 

I recall 2wire, now part of Arris, were a contributor to the development of the standards in the Broadband Forum.  If you look at the specifications for the Arris cable modems, as used by VM, they offer TR-069.

[IPFreely]

I think you've solved the mystery in that case. They've eschewed SNMP in favour of TR69 and it only listens in router mode.

Thanks!