Ericsson IP Phones and Option 43

Axford M.F. M.F.Axford at
Fri May 8 12:39:39 UTC 2009


We're about to deploy some IP Phones here and of course they want some DHCP options. (The people running this project would like this by the end of next week but of course haven't provided a phone to test with yet!)

>From the limited Documents I've received it appears that the phones will provide a Vendor Client Identifier (Option 60) of "Ericsson IP-Phone" and will expect a number of options via Vendor Encapsulated Options (option 43).

I have no problems with creating a config section based on the VCI (we're already using this to match PXE clients and looking to do the same for Mac Netbooting). From the man pages I believe it is possible to specify option 43 as a long string or by creating an option space. Ideally I'd like to use the option space as this will make configuration easier. However in this instance I'm not sure if this is possible.

>From the Documentation it looks like option 43 will be made up of:
String length (0x11), the string "Ericsson IP-Phone", tag 01 type string, tag 04 type string, tag 05 type string.

The example I've got is:
option vendor-encapsulated-options 11:45:72:69:63:73:73:6f:6e:20:

Split up this gives:
Length 0x11 - 17bytes - Text "Ericsson IP-Phone"
Tag 01, Length 9:

Tag 02, Length 9:

Tag 03, length 4: 1234

So my question is: Is there a way I get the "Ericsson IP-Phone" part into the option 43 packet if I use a config something like:

Option space EricssonPhone;
Option EricssonPhone.webserv code 1 = text;
Option EricssonPhone.proxyserv code 2 = text;
Option EricssonPhone.proxyport code 3 = text;
Option EricssonPhone.domain code 4 = text;
Option EricssonPhone.vlan code 5 = text;

If substring( option vendor-class-identifier,0,17) = "Ericsson IP-Phone" {
        option vendor-class-idendifier "Ericsson IP-Phone";
        vendor-option-space EricssonPhone;
        option EricssonPhone.webserv "";
        option EricssonPhone.proxyserv "";
        option EricssonPhone.proxyport "1234";


Mike Axford
University of Southampton

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