ONVIF Profile Q Aims To Change Discovery and Default Passwords

With Profile Q, a device will not have any default password and when one first connects, in a default state, you are then required to setup a password.

Good. I've long been an advocate of this.

Hi John,

Just a question and a few notes:

question: "Eliminates requirement of time synchronization which has caused connectivity issues." - are you talking about requirement to device to have NTP ON, or requirement to use HTTP-Digest (that is not so fragile to time syncronisation), or something else?

note1: from ONVIF press-release they say about 6 month validation period, and keeping in mind (a) their tick-tack scheme of releases winter/summer and (b) their practice of having something implemented by key players before releasing drafts, there is a high probability that there will be devices with official Profile Q conformance at the end of this summer.

note2: ONVIF-style Discovery is also an obligatory part of Profile S, but Profile Q requires it to be turned ON by default and after so-called "hard factory reset". In conunction with DHCP/ZeroConf, ONVIF client can reliably discover all new devices and there is no need for manual IP assignment

note3: the easiest position have manufactures that have no own VMS - they do not need any significant changes (as all features of Profile Q should be already in-place). Issues that you are highlighting are more not about devices itself, but about infrastructure/ecosystem.

Regarding ZeroConf and the "169.xxx.xxx.xxx" addressing point. They are not the same thing. The "169.xxx.xxx.xxx" is called "Link-Local" and is the self-assigned address you get when no DHCP server is availablea and you don't have a static addess.

ZeroConf is a way to announce and/or discover what address you DO have, whether it's DHCP, Static, or Link-Local, using multicast DNS (mDNS). However, before ZeroConf, Link-Local addresses were, in my opinion, not useful, because what good was having a device get an address on the local network if you couldn't find out what it was.

Zeroconf is, at its core, network service advertisement and discovery using multicast-DNS.

Link-local addressing predates Zeroconf discovery by almost a decade. Windows has supported it since Windows 98. I would say that most people's first exposure to it was when their Windows machines couldn't connect to the network, they checked their settings and saw an address beinging with 169.xxx. I know I did, I did not know what the 169 meant until years later. Link-local is often thought to be part of Zeroconf, because they're often used together. That, and link-local addresses are useless unless there is some discovery method in use, so I think that's why they are often confused.

A few years back, I implemented Zeroconf on Mercury's access control boards. I would be very interested in how other devices implemented it. That said without mDNS, a device should not be claiming Zeroconf support.

I'm surprised that there's no mention in the article about Profile Q's support for Transport Layer Security with secure communication via certificate/key authentication between device/client.

Any reason for this omission? I was under the impression that secure comms was a big part of Profile Q.

Ah, that would make sense. Thanks for the info.

Official ONVIF Response:

Q: Does it require hostname to resolve ip address?

A: This is DNS. Covered in section 7.2.1. So, yes.

Q: How common for cameras to be shipped with different hostnames? - seems no.

A: Regardless of how a camera is shipped, hostname -> IP address is dependent on an installer setting up DNS records.

Many manufacturs ship cameras with the hostname set to model-serial (e.g. MODEL-SERIAL).

Q: ONVIF clients are using ws-discovery to navigate local network devices, and it know nothing about ip address origin. How does Profile Q help?

ONVIF clients broadcast a WS-Discovery PROBE request over multicast. Cameras respond with their scopes.

When a WS-Discovery device joins the network (boot, CAT5 connection, etc.), it broadcasts a WS-Discovery HELLO over multicast. Clients can listen for these packets, and immediately send a PROBE to the specific device to determine if it’s of interest.

Q: So from an ONVIF perspective - zeroconf is just linklocal, moreover their specs sometimes refer it as linklocal instead of zeroconf. Whats the difference?

A: ZeroConfiguration and IPv4 LinkLocal are used interchangeably, although technically IPv4 LinkLocal is just a subset of ZeroConfiguration. The ProfileQ spec intends for ZeroConfiguration to be defined as IPv4 LinkLocal (from Section 9: “… IPv4 Link Local Address (defined as ZeroConfiguration capability) …”).

Q: Do devices that are claiming zeroconf functionality have mdns inside?

ZeroConfiguration includes the concept of multicast DNS. IPv4 LinkLocal does not. Profile Q intends the latter.

Let us know if you have any more questions!

ONVIF Response:

Manufacturers who have a good ONVIF Profile S, G or C implementation already may find Profile Q a very incremental addition to their product's capabilities. In other words they may very well be supporting the majority of functions specified already.