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!

A question that has often been asked by those working with these devices;

"How can you reboot/reset an i2002/i2004 without unplugging it?"

Well there is good news. You can reboot them without physically disconnecting the CAT 5e/6 cable (or the power supply if your not using the PoE functionality). The bad news is the key sequence is fairly complicated. The following key sequence will also work for all of Nortel's Internet telephones (i2002, i2004, i2007, 1120e, 1140e, 1150e).

Here's the key sequence you'll need to follow;

1. Mute key,
2. Up Navigation key,
3. Down Navigation key,
4. Up Navigation key,
5. Down Navigation key,
6. Up Navigation key,
7. Mute,
8. 9,
9. Goodbye key

Here's a graphic that might make it a little easier to understand;


Once you strike those keys the i2002/i2004 Internet Telephone will reboot itself at which time you can reconfigure the phone by striking the four soft keys just below the display while the "Nortel Networks" logo displays on the LCD.

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!

We generally deploy just two phone models, the Nortel i2002 and the Nortel i2004. The phones support the exact same feature set, the only difference being the size of the display and the number of "keys" or appearances. The Nortel i2002 supports the following features;

Here's a picture of the Nortel i2002 Internet Telephone.

• 4x24 Character LCD
• Headset Jack
• Handsfree speaker phone
• 802.3af PoE (Class 2)
• Internal Switch (10/100Mbps)
• XAS (Application Gateway) support

Here's a picture of the Nortel i2004 Internet Telephone.

• 8x24 Character LCD
• Headset Jack
• Handsfree speaker phone
• 802.3af PoE (Class 2)
• Internal Switch (10/100Mbps)
• XAS (Application Gateway) support

You can see that both phones are fairly similar and they run the same software/firmware. We use a single CAT5e/CAT6 cable drop to connect the phone and then connect the end-user's desktop/laptop to the PC port on the phone. We employ QoS to guarantee that the voice VLAN gets the appropriate priority and queuing over the data VLAN.

How do you get started?

I will outline how we configure the i2002/i2004 phones for LLDP (Link Layer Discovery Protocol / 802.1ab) and LLDP-MED for the voice VLAN assignment. We configure every phone with the same configuration throughout the enterprise. We rely on LLDP and DHCP to provision the phones with site specific information such as voice VLAN, IP address, Succession Call Server, etc.
You can of course statically configure all that information into the phone manually but then you'd need to visit the phone anytime you needed to make a change and if you had to replace a phone you'd need to re-program it to match the original settings (assuming you had them documented somewhere).

As of August 3, 2007 the phones are shipping with firmware 0604D31. This firmware does NOT support LLDP and will not have an option to enable LLDP. In order to properly deploy LLDP on the Nortel i2002/i2004 Internet telephones you'll need to be running firmware 0604DBG or later. In order to upgrade the phone you'll need to get it to connect to the Call Server (that means you'll probably need to static the configuration through the phone). Once the phone connects to the Call Server it will automatically pull down the latest firmware that has been installed on the Call Server.

If you don't have a PoE (Power over Ethernet) switch you'll need to use a power supply to power the phone. As the phone is booting you’ll need to strike the four soft buttons at the bottom of the display window while the text “Nortel Networks” is being displayed. This will allow you to confirm that the phone is configured properly from the factory.


You should configure the i2002/i2004 IP phone as follows; (depending on what version of firmware is installed on the phone you might not see all the options below)

• EAP Enable? [1=Y, 0=N]: 0 (Default - no EAP authentication)
• LLDP Enable? [1=Y, 0=N]: 1 (we are going to need LLDP)
• DHCP? [0-No, 1-Yes]: 1 (we are going to need DHCP)
• DHCP: 0-Full, 1-Partial: 0 (we want to get a full DHCP response)
• Speed[0-A,1-10,2-100]: 0 (Auto negotiation)
• Cfg XAS? [0-No, 1-Yes]: 0 (Default - we don't use XAS)
• Voice 802.1Q[0-N,1-Y]: 1 (Default - mark voice VLAN pakcets with 802.1Q tags)
• Voice VLAN? [0-N, 1-Y]: 1 (we want a Voice VLAN since we'll be attaching a PC to the PC port)
• VLAN Cfg? 0- Auto, 1-Man: 0 (Automatically configure the Voice VLAN)
• LLCP MED? 0-No, 1-Yes: 1 (Voice VLAN will be configured using LLDP-MED)
• LANFILTER? [0-No, 1-Yes]: 1 (filter Voice VLAN packets from the PC port)
• Ctrl pBits[0-7,8-Au]: 8
• Media pBits[0-7,8-Au]: 8
• PC Port? [0-OFF, 1-ON]: 1 (Default - leave PC port enabled)
• Speed[0-A,1-10,2-100]: 0 (Default - leave Autonegotiation enabled on PC port)
• Data 802.1Q[0-N,1-Y]:1 (Default - mark data VLAN packets with 802.1Q tags)
• DATA VLAN? [0-N, 1-Y]: 0 (Default - we're going to use the PVID on the switch port)
• Data pBits[0-7,8-Au]:8
• PCUntagAll? 0-No, 1-Yes: 0
• DUPLEX [0-AUTO, 1-FULL]: 0
• GARP Ignore? [0-No, 1-Yes]: 0
• PSK SRTP? [0-No, 1-Yes]: 0 (Default - you can encrypt the RTP stream if necessary)

If everything has been setup and configured properly (including the Call Server, network switch, DHCP server, etc) the phone will boot and will prompt you for a "Node Number" and "TN".

I've jumped the gun by telling you how to configure the phone before configuring all the back-end equipment, including the Nortel Ethernet Routing Switch 5520 PwR and the DHCP server. In my next installment I'll cover how to configure the Nortel Ethernet Routing Switch 5520 PwR and what you'll need to configure in your DHCP server.

Troubleshooting

If the phone hangs with “Starting DHCP…” on the display for more than 60 seconds you’ll need to start troubleshooting. You'll need to confirm that the phone is configured properly and you'll need to confirm that it's grabbing the proper IP address from the DHCP server. Just remember that the MAC address can be found on the back of the phone.