External DHCP and BCM50 / UNISTIM Phones 2

[robl3000]

If I am using an external DHCP server (not the one built into the BCM50), what options need to be included to configure Nortel IP phones? i.e., option 42 sets the NTP servers for DHCP clients.

I am looking for either a how-to or a list of options that need to be defined to fully replace the built-in DHCP server of the BCM50.

Thanks!

 

[CTCINY]

Well you won't be able to use the full DHCP setting. But you will need to published IP address of the system, the voice and data VLAN settings and full/half duplex settings.

 

[Deweyhumbolt]

Options is over my head. Basically, make sure DHCP is off on the BCM. When you configure IP tels, pick Partial DHCP and enter the BCMs IP at S1 entry. DHCP server should give the IP set an address and the IP set can find the BCM.

 

[robl3000]

Dewyhumbolt:

Hrmmmm. So there should be no problem having the BCM50 working as a "partial DHCP" server with a full external DHCP server in place?

I know in traditional IP data networks, you can only have one DHCP server on a subnet -- multiple servers would cause major problems.

I try to configure everything with DHCP so that no device has to be "manually" re-programmed if something changes on the network.

 

[Deweyhumbolt]

You need a Static for the BCM. My first move was, turn off DHCP server capability on BCM. No conflict. Allow your server to give the IP sets addresses, but when configuring each individual IP set, choose Partial. It just means your server tells the IP set its address and you tell the IP set the BCMs address.

 

[gm85]

Which product are you using for your DHCP server? Microsoft DHCP? Cisco? Linux DHCPD?

For Full DHCP (Which makes a lot more sense). What you need to do is configure option 128 on the DHCP server. Option 128 uses the following string: Nortel-i2004-A,<BCM IP>:<Port>,1,10.

So for instance, if your BCM is 10.1.1.10 and the port is 7000 (which is default for the BCM series), you'd configure it with the following settings.

Option 128: Nortel-i2004-A,10.1.1.10:7000,1,10.

(I should note that although the string states "i2004", it is used by all nortel IP phones. Also, remember the trailing period. it's often overlooked)

 

[robl3000]

gm85:

This is using a Linux dhcpd server.

I am comfortable with setting up custom dhcp options, but I couldn't find any documentation as to what the phones expect.

I am assuming Option 128 (Nortel-i2004-A) Corresponds to S1? Would Option 129 be S2 as well?

I will give Option 128 a try, as I would prefer to do full DHCP for the phones.

I am not sure it matters, but the phones here will be 1220 and 1230s.

 

[gm85]

Nortel IP Phones will respond to DCHP options 128, 144, 157, 191, 251 in case any of those options are used by other vendors.

If you would like to add an S2 server, the information is appended to the end of the DHCP option 128 by using a semicolon. The full syntax of the DHCP command is
Nortel-i2004-A,<S1 IP>:<S1 Port>,<S1 Action>,<S1 Retry Count>;<S2 IP>:<S2 Port>,<S2 Action>,<S2 Retry Count>.

I always leave <S1 Action> as 1 (Never been able to figure out what the other options do)
<S1 Retry Count> and <S2 Retry Count> indicate how many times the phone will try contacting that server before moving onto the next. I usually leave it at 10

So for instance if you have
S1: 10.1.5.5:5000
S2: 10.1.5.6:5000
And a retry count of 10 for each
The command would be
Nortel-i2004-A,10.1.5.5:5000,1,10;10.1.5.6:5000,1,10.

My only question is if this is communicating with a BCM50, what is the S2 address going to be used for?

Now this documentation pre-dates the 1200 series (and the 1100 series I think... I should look at the date of the document). However I don't see why it wouldn't be compatible with the newer series since it wouldn't make sense for nortel to require additional DHCP commands for different models of sets connecting to the same BCM system.

 

[aragon]

The S2 address is used for redundancy in case the S1 server is unresponsive.