Michael McNamara

It would seem a great many people are running into this error so I thought I would post a quick article that would help all those looking for a solution to their problem. The Nortel i2002/i2004 (any Nortel IP phone) will return the error "DHCP parse error" if the DHCP server returns DHCP option 128 with an invalid format.

In one of my first blog posts entitled "DHCP Options (VoIP)" I outlined the DHCP options and the format that the phone expected. Kenneth quickly pointed out that I had fat-fingered the example DHCP string omitting the semicolon between the values for the primary Call Server (S1) and the secondary Call Server (S2). (I've since fixed the original post)

Here's the format the DHCP option code 128 which the IP phones expects to be returned from the DHCP server when the IP phone is configured for "Full DHCP";

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 (.).

If you are using an ISC DHCP server (this is generally included with any of the Linux distributions) you can refer to my article entitled "ISC DHCP Server (Nortel VoIP)" for information on how to setup and configure the ISC DHCP server to work with Nortel IP Telephony.

Cheers!

Nortel has just released UNIStim firmware release v2.3. There were some major enhancements made in firmware release v2.2 that enhanced DHCP provisioning for the 1100 series and i2007 phones. With release v2.3 the same new enhanced DHCP provisioning is now available for the i2001, i2002 and i2004 (Phase II only) phones.

While I haven't personally started testing the new firmware release I'd like to discuss the new DHCP options that will be available to phones running this software release. It's really important that we not confuse the legacy DHCP options with these newly available DHCP options. Unless your phone is running a firmware release documented below you should ignore this post entirely!

• 0604DBP for i2001, i2002, i2004 (Phase 2 Only)
• 0621C4V for i2007
• 0623C4N, 0624C4N, 0625C4N and 0627C4N for 1110, 1120E, 1140E and 1150E respectively
• 062AC5L for 1210, 1220 and 1230

Nortel Internet Telephones running the firmware documented above will support a new DHCP option and vendor class "Nortel-i2004-B". The format of the newly defined "Nortel-i2004-B" DHCP option is;

Nortel-i2004-B,param1=value1;param2=value2;param3=value3;...

The above table was taken directly from the Nortel release notes.

An example configuration string would look something like the following;

Nortel-i2004-B;s1ip=47.11.62.20;p1=4100;a1=1;r1=255;s2ip=47.11.62.21;
p2=4100;a2=1;r2=2;xip=47.11.62.147;xp=5000;xa=g;unid=Main-tower;
menulock=p;vq=y;vcp=3;vmp=4;vlanf=y;pc=y;pcs=a;pcd=a;dq=y;dv=y;dvip=60;
dp=5;pcuntag=y;lldp=y;pk1=438A64FC24127C23;pk2=64FC23CD24AB1413;
cachedip=y;igarp=n;srtp=n;dim=y;bt=y;

You'll obviously need to be careful with using the "lldp" option in DHCP because it could hang the IP phone if you don't have the network switch setup properly.

Cheers!

I've received quite few messages from folks trying to setup and configure the ISC DHCP server that often comes bundled with all the major Linux distributions for Nortel Internet Telephony. Nortel has several "Technical Configuration Guides" that outline how to configure Microsoft's DHCP Server but I don't believe they ever discuss the ISC DHCP server.

I will admit that I really don't use the ISC DHCP server these days. We've been using Lucent's VitalQIP IP Management software to manage our internal BOOTP/DHCP/DNS/DDNS needs for the past 10 years.

However, since there was so much interest I decided to setup a lab (at home) with a i2002 phone and a server running CentOS v5.0. I installed dhcp-3.0.5-7.el5 via YUM and came up with a sample dhcpd.conf file that anyone should be able to modify to meet their specific needs.

#
# DHCP Server Configuration file.
#   see /usr/share/doc/dhcp*/dhcpd.conf.sample 
#
# Sample dhcpd.conf file for Nortel Internet Telephony
#
# Notes: example dhcpd.conf file to illustrate how to configure Nortel
# Internet Telephone specific DHCP options for i2002/i2004 Internet
# Telephones and 2210/2211 Wireless Phones.
#
# *** WARNING *** WARNING *** WARNING *** WARNING ** WARNING ***
#
# This is just an sample file with specific IP information. You'll
# need to customize this file to your specific IP address scheme
# before you can use it in your environment.
#
# *** WARNING *** WARNING *** WARNING *** WARNING ** WARNING ***
#

ddns-update-style none;
not authoritative;

option nortel-callserver code 128 = string;
option nortel-2245 code 151 = ip-address;

# Vendor Class for i2002/i2004/1120e/1140e/1150e Internet Telephones
class "Nortel-i2004-A" {
match if substring (option vendor-class-identifier, 0, 14) = "Nortel-i2004-A";
option nortel-callserver "Nortel-i2004-A,192.168.200.2:4100,1,5;192.168.200.2:4100,1,5.";
option vendor-class-identifier "Nortel-i2004-A";
next-server 192.168.0.10;
}

# Vendor Class for 2210/2211 Wireless Phones
class "Nortel-221x-A" {
match if substring(option vendor-class-identifier, 0, 13) = "Nortel-221x-A";
option nortel-callserver "Nortel-i2004-A,192.168.200.2:4100,1,5:192.168.200.2:4100,1,5.";
option nortel-2245 192.168.200.25;
option vendor-class-identifier "Nortel-221x-A";
next-server 192.168.0.10;
}

# Network Definition
shared-network "mynetwork" {
 subnet 192.168.0.0 netmask 255.255.255.0 {
 option subnet-mask 255.255.255.0;
 option routers 192.168.0.1;
 option domain-name "acme.org";
 option domain-name-servers 192.168.0.1;
 default-lease-time 28800;
 max-lease-time 86400;
 
   # IP Address Pool for generic devices
   pool {
      range 192.168.0.50 192.168.0.100;
      deny members of "Nortel-i2004-A";
      deny members of "Nortel-221x-A";
   }

   # IP Address Pool for i2002/i2004/1120e/1140e/1150e
   pool {
      range 192.168.0.150 192.168.0.175;
      allow members of "Nortel-i2004-A";
      deny members of "Nortel-221x-A";
   }

   # IP Address Pool for 2210/2211
   pool {
      range 192.168.0.176 192.168.0.199;
      deny members of "Nortel-i2004-A";
      allow members of "Nortel-221x-A";
      }
 }
}

The release of v3.x software for the Motorola WS5100 and v1.x software for the Motorola RFS7000 finally supports the deployment of Layer 3 Access Ports (APs that could be deployed across a Layer 3 network as opposed to those that can only be deployed across a Layer 2 network).

The latest release of firmware for the AP300 will first attempt to locate a wireless switch for adoption via a Layer 2 broadcast request. If it's unable to locate a wireless switch it will make a DHCP request for an IP address. If the DHCP response does not include option 189 (string) it will make a DNS request to try and locate the wireless switch.

There are two ways the Access Port can locate the Wireless LAN Switch (WS5100/RFS7000) in Layer 3 mode;

• DHCP Option
  
• DNS Query
  

In a previous article we reviewed how to configure a Nortel Ethernet Routing Switch 5520 using ADAC/LLDP (802.1ab) so a Nortel Internet Telephone could discover the voice VLAN ID automatically without manually configuration of the phone.

If you don't have a switch that supports ADAC/LLDP you can still utilize automatic VLAN assignment using DHCP. I've actually used this method (before Nortel supported LLDP) and it works well but can sometimes be difficult to troubleshoot.

You'll need to configure DHCP option 191 (string) with the following syntax;

VLAN-A:vvvv.

Where: "VLAN-A" Option 191 begins with this string for all Nortel IP phones.
"vvvv" The VLAN ID for the voice VLAN in decimal

1. The phone will boot up and make a DHCP request for option 191 in the Default VLAN of the port connecting the phone.
2. If the phone receives a response to it's request it will issue a DHCP Release of the address it received in Step 1.
3. The phone will make a second DHCP request in the VLAN that was returned in option 191. The phone will be requesting DHCP option 128 from the DHCP server, this will include the Call Server information. (Note: if you use a sniffer you will see that the DHCP packets will have an 802.1q header with the appropriate VLAN ID)
4. The phone will connect to the Call Server specified in DHCP option 128 and will prompt the user for the Node ID and TN information.

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.

• “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

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

• 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