24th October 2007

DHCP Options (VoIP)

posted in VoiceOverIP | 1,775 views | Print This Post

In this post I’d like to cover the DHCP options you’ll need to automatically configured the Nortel i2002/i2004 Internet Telephones as they boot. These DHCP options will actually work with any of Nortel’s Internet Telephones including the i2002/i2004/i2007/1120E/1140E and 1150E.

You’ll need to add a custom vendor DHCP option with a code of “128″ as a string value. You should name this DHCP option as “Call Server Information”. The value of this DHCP option will use the following format;

Nortel-i2004-A,iii.iii.iii.iii:ppppp,aaa,rrr;iii.iii.iii.iii:ppppp,aaa,rrr.

Where the following values are;

  • “Nortel-i2004-A” = Option #128 begins with this string for all Nortel IP phone sets
  • “iii.iii.iii.iii” = the IP Address of the Call Server (S1 or S2)
  • “ppppp” = port number for the Call Server
  • “aaa” = the Action for the Server
  • “rrr” = the Retry Count for the Server

The IP Address must be separated from the port number by a colon (:). The parameters for the Primary (S1) and the Secondary (S2) Call Servers are separated by a semicolon (;). The string must end a period (.).

For this example, enter the following:

Nortel-i2004-A,10.1.1.10:4100,1,5;10.1.1.20:4100,1,5.

This would equate with the following values;

  • Call Server S1 = 10.1.1.10
  • Port S1= 4100
  • Action S1= 1
  • Retry S1= 5
  • Call Server S2 = 10.1.1.20
  • Port S2 = 4100
  • Action S2 = 1
  • Retry S2 = 5

You can use the vendor class of “Nortel-i2004-A” if you’d like to build different scopes within your DHCP server. A default scope for all general devices and then a specific scope for any device that requests the vendor class of “Nortel-i2004-A”.

Let me make this comment… if your DHCP server mistakenly returns a DHCP response that does NOT include DHCP Option 128 the IP phone will just sit at the “Starting DHCP…” prompt. You need to make sure that you return DHCP Option 128 in the DHCP response to the phone.

This all assumes that you’ve setup a DHCP relay on the Voice VLAN on the core ERS 8600 switch or whichever switch you might be using as the router for that VLAN.

I’ll review the basic configuration of the ERS 8600 (core) in a subsequent post as it applies to the example configuration I’ve laid out in the past few posts.

Please feel free to drop a line if you have questions.

Cheers!

This entry was posted on Wednesday, October 24th, 2007 at 7:57 pm and is filed under VoiceOverIP. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.

There are currently 8 responses to “DHCP Options (VoIP)”

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  1. 1 On January 22nd, 2008, Anonymous said:

    Dear Michael,

    did I get it right that you may but need not define an option code string value starting other than “Nortel-i2004-A” for any of the IP phones you listed?

    What I am especially interested in is the value used for the i2033 IP Phone, which I could not find anywhere.

    Your answer would be a great help to me. Thanks in advance

    Sabine

  2. 2 On January 25th, 2008, Michael McNamara said:

    Hi Sabine,

    The i20033 IP conference phone is a really nice product. I believe it is configured in the Call Server as an i2001 IP telephone.

    I was unable to “officially” confirm that it uses the same DHCP vendor class “Nortel-i2004-A” and same DHCP option code “128″. With that said I would suspect it does use those same DHCP vendor class and DHCP option code.

    In fact I believe every IP phones uses the same DHCP vendor class with the exception of the Nortel IP Wireless Phones (2210,2211) which use “Nortel-221x-A”.

    If you have an account with Nortel’s website you can find a lot of very good information in this document;
    http://www142.nortelnetworks.com/techdocs/IP2033/pdf/553-3001-368_26.00_IPLDIO.pdf

    You could also use a sniffer to capture the DHCP request and see what DHCP vendor class the phone is using along with what DHCP options it is requesting.

    Let us know if you’re having any issues getting the i2033 running.

    Cheers!

    PS: If your not already aware I believe you need to strike the three soft keys while the phone is booting and “Nortel” is shown on the display in order to get into the configuration mode.

  3. 3 On January 27th, 2008, Anonymous said:

    Hi Michael,

    thanks a lot for the very helpful information!

    According to the document you mentioned, “Nortel-i2001-A” in fact seems to be the right entry. I´ll have that tried out (because I myself am no networking specialist but a technical writer having to mention that entry in some documentation) and report to you whether it worked.

    Cheers
    Sabine

  4. 4 On January 28th, 2008, Kenneth, dk said:

    If anyone should happen to copy and paste as I did :)
    Just remember the semicolon is important in this string : Nortel-i2004-A,10.1.1.10:4100,1,5;10.1.1.20:4100,1,5.
    You will get a DHCP parse error if u dont.
    Besides from this it actually works. Thanks

  5. 5 On January 28th, 2008, Michael McNamara said:

    Hi Kenneth,

    Good catch! I’ve fixed the original post!

    Thanks,
    Mike

  6. 6 On July 2nd, 2008, Michael McNamara said:

    Rick left the following message comment (just before I migrated the blog to WordPress);

    I’m trying to get the phone menu to partially lock down (config and diagnostics) on an 1140e phone via DHCP, and keep getting parse errors because the format isn’t right.
    Do you know where to slide in “PARTSECURE” in the string, assuming only one s1 address?
    thanks! Rick

    It’s going to partly depend on which version of firmware the phones are running Rick. If you are running a firmware prior to 0625C4N (for the 1140E) you’ll need a DHCP string similar to the following;

    “Nortel-i2004-A,10.1.1.10:4100,1,5;10.1.1.20:4100,1,5;0.0.0.0:0,0,0;0.0.0.0:0,0,0;PARTSECURE.”

    Please make sure to end the string with a period.

    I’ll honestly say I haven’t tested this so please let me know what you find. It’s my understanding the that SECUREMENU or PARTSECURE options need to appear after the S4 value. In the above example I have real values for S1 and S2 but dummy values for S3 and S4.

    With firmware 0625C4N or later you can use the Nortel-i2004-B format which is documented in my post Nortel IP Phones - UNIStim release v2.3.

    Nortel has since release UNIStim v3.0 which expands support for the new Nortel-i2004-B format to the i200x series phones.

    Good Luck!

  7. 7 On July 3rd, 2008, Rick said:

    M&M,

    Thanks for the assistance. I think you’re right about the string syntax, because when I put in the dummy s2-4 info, I no longer get the parse errors, but it still doesn’t lock down the phone’s config menu. I am using firmware 0625C3C, which I am not sure even allows for this command. NoTell, er, Nortel, isn’t much help in the matter. I think we’ll have to manually lock the menu for each phone we deploy until we get the latest and greatest code and go with the -B format. Mahalo for helping out. -Rick

  8. 8 On July 5th, 2008, Michael McNamara said:

    Thanks for the follow-up Rick.

    I will test this feature and let you know what I find. Nortel can be very helpful, but just like any large organization it can be difficult getting to the “right” people. And the voice resellers can be equally frustrating, again depending on whether you get to the “right” people.

    I’ll let you know what I find.

    Mike

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