ADAC/LLDP-MED Provisioning in Dynamic Campus Environment

[Stefan Herbst]

Hello,

I wanted to throw out some past experiences I have had with IP Telephony auto configuration (ADAC & LLDP-MED) on the ERS4000/5000 switches. I hope to get some feedback to what others have done and their experiences and also some feedback on a proposed configuration.

Using ADAC with DHCP on ERS4000/5000
In this specific design ADAC was used to detect the phone and modify the port settings to UntagPVID only and add the voice vlan (tagged) to the port dynamically. The IP phone would initially boot onto the data VLAN where it would request an address via DHCP. DHCP options were used to provide the voice VLAN. Then the IP Phone would request an address via DHCP on the voice VLAN and Nortel-i2004-B options were used to provide provisioning information to the IP Phone. This worked well but we had some frustrations with ADAC.
1. Multiple uplink ports (daisy-chained topology).  There was no support for more than one uplink.
2. Manually assigning a port in the voice VLAN – this was needed for analog/ip gateways for fax machines etc. If the changes were made on a port while ADAC was enabled the change would be reverted if the switch was rebooted or if ADAC was disabled on the port.

I understand the above has been fixed in current code versions however I am wondering if anyone has used ADAC in an dynamic environment where VLAN adds/moves/changes and sometimes topology changes happen frequently? I am hesitant to use this feature in non-static environments and would be curious to others experiences.

Using LLDP-MED with DHCP on ERS4000/5000
In this specific design LLDP-MED was used to inform the IP Phone of the Voice VLAN. Once the IP Phone was set to use the correct voice VLAN it requested an DHCP address and Nortel-i2004-B options were used to provide provisioning information to the IP Phone. Overall this worked very well, unlike the ADAC option above LLDP-MED removes the requirement for the IP Phone to first request an DHCP address on the data VLAN to get the Voice VLAN-id via DHCP. The downside is that the edge ports were manually configured as UntagPVIDOnly and therefore the voice VLAN was always ‘exposed’ on that port. Also QoS was not dynamically applied and manual policies needed to be configured.

Desired (but not implemented) Solution
Use ADAC for the IP Phone detection, edge port configuration change and automatic QoS. (which can support more than one uplink and also manual static voice VLAN port configuration)
Use LLDP-MED to send voice VLAN information to the IP Phone.
DHCP options are only used on voice VLAN (TFTP/HTTP provisioning or and Nortel-i2004-B options)
Does anyone have experience with this type of configuration?
Is their any significant limitations between ERS3500/4000/5000 when using the above method?
Is the above method possible?

Comments, questions and thoughts are appreciated.
Stefan

 

[Telair]

Your desired solution is certainly possible.  One guy in my company got ADAC and LLDP to work together so he could take a phone out of the box, plug it in to the network port at the desk and he just needed to program the extension of the phone and it worked straight away.  I think he made promises of souls to dark gods to get it all working together, but he did get it working that well.

Typically the way I have been asked to setup voice network on switches is pretty basic, but easy with no ADAC or LLDP involved.  Just provision a voice VLAN and give it an 802.1p priority of 5 on the switches.  Add the voice VLAN to the user ports but set the port PVID to the data VLAN.  Then setup DHCP to pass the voice VLAN info to the phone on bootup and away you go.

[pat2012]

I agree with Telair. I've also been able to implement ADAC and LLDP-MED on my network using ERS 4500's, but I didn't have to promise any souls to dark gods...  LOL!!

If you like I can post some configuration examples for you to look at.  It works very well - separate voice and data VLANs, no voice VLAN exposure etc.  I even have ERS 2500's providing DHCP for the phones while the PCs get their IPs from a typical Microsoft DHCP server.

OK. I might as well post some of the config. 

#vlan create 330 name DATA type port
#vlan create 340 name VOICE type port 1 voice-vlan

Enable 802.1Q tagging on all fibre uplinks and enable the filtering of untagged frames.
#vlan ports 25,26 tagging tagall filter-untagged-frame enable

Configure access ports 1-24 {1-48} to allow untagged data VLAN 330 and tagged voice VLAN 340

#vlan port 1-24{1-48} tagging untagpvidonly
#vlan members add 330 1-23,25,26
#vlan port 1-23{1-47} pvid 330
Note, in case you're wondering, port 24 was not added to the DATA VLAN because it was assigned to the management VLAN - not shown in this config example.

Enable spanning tree fast learning on all ports.
#interf fa 1-26
#spanning-tree learning fast

It is recommended to also enable BPDU filtering on all access ports.
#interf fa 1-24{1-48}
#spanning-tree bpdu-filtering enable
#exit

Now for the ADAC/LLDP-MED configuration.
#vlan ports 1-23{1-47} filter-unregistered-frames disable
#adac voice-vlan 340
#adac uplink-port 25,26
#adac op-mode tagged-frames
#adac traps enable
#adac enable
#interf fa 1-23{1-47}
#adac tagged-frames-tagging untag-pvid-only
#adac enable
#lldp tx-tlv port 1-23 {1-47} local-mgmt-addr port-desc sys-desc sys-name
#lldp status txandrx config-notification
#lldp tx-tlv med extendedPSE med-capabilities network-policy
#lldp med-network-policies voice dscp 46 priority 6 tagging tagged vlan-id 340
#exit
Most of this is default in the latest version of the code I believe.

QoS configuration.  In this case we only have to change the default QoS queue set to 4 and reboot.  ADAC/LLDP takes care of the rest.
#qos agent queue-set 4
#save config
#boot

I hope this helps.

Avaya - "The power of We".