LLDP-MED
Location Identification
for Emergency Services
Emergency Services Workshop, NY
Oct 5-6, 2006
Manfred Arndt (manfred.r.arndt@hp.com)
Scope
 ANSI/TIA-1057 – LLDP Media Endpoint Discovery (LLDPMED)
– Extension to base LLDP standard to support multi-vendor interoperability
between VoIP endpoint devices and IEEE 802 networking infrastructure
elements, including physical location discovery (among other things)
– Developed by TIA TR-41.4 (VoIP Standards)
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What is LLDP-MED?
ANSI/TIA-1057, LLDP Media Endpoint Discovery:
 Developed by TIA TR-41.4 (VoIP Standards)
 Provides VoIP-specific extensions to base LLDP
protocol
– New TLVs for:
•
•
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Location identification, including to support ECS
LAN policy discovery (VLAN, Layer 2 priority, DSCP)
Fine grained power management for PoE devices
Inventory management
– Endpoint move detection and reporting
– “Fast Start” protocol behaviour, to improve timeliness
– SNMP MIBs definition to support management of above
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Location TLV
 Enables Physical Location Services, including Emergency Call Service (ECS)
– Supports NENA E911 and other location services (for example NENA TID 07-501)
 Multiple Location Formats Supported, and easily extensible
– Coordinate-based LCI subtype as defined by IETF RFC 3825
– Civic Address LCI subtype defined by draft-ietf-geopriv-dhcp-civil-09 (approved, in RFC Editor queue)
– ELIN subtype, to support traditional PSAP-based Emergency Call
– One or more formats may be used simultaneously for different endpoint requirements
 Two ECS methods supported (End-device & Notification based)
– Switch advertises periodic location info for endpoint to use
– Switch sends notification whenever a new endpoint is detected or an endpoint moves
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End-device based location
Method 1 - Ideal for smart clients (e.g. SIP phones)
1.
A management application or an LIS programs the location identification into
network devices using SNMP and the LLDP-MED MIB
–
2.
Every port may advertise a unique coordinate based, civic based, and/or ELIN location value
Network devices advertise periodic LLDP-MED frames containing the location
identifier
–
Endpoint has location information to use immediately in the call setup
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Notification based ECS (E-911)
Method 2 - Infrastructure Based for smart management tools
1.
2.
3.
IP phones advertises their MAC/IP, and telephone capability to network device
via periodic LLDP-MED frames
Network device send an SNMP event notification to a management application
or an LIS whenever a new IP phone has directly connected or disconnected
The management application or LIS will poll the IP phone information from
network devices using the LLDP-MED MIB, to ensure integrity
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VoWLAN Location Considerations
 Emergency Services, Some Thoughts ...
– AP physical location may be suitable for many E-911 requirements
– Wireless client would quickly discover new physical location on roaming
– Ethernet switches need to be configured with physical location anyway, to support
wired IP phones
– AP could auto-discover it’s physical location via LLDP from wired network
– For higher accuracy, AP could triangulate and advertise relative client location using
802.11 specific frames or LLDP extensions (future work)
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Summary
 LLDP-MED provides several technical advantages for ECS location
discovery
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Existing, well defined standard that is easily understood
Simple and effective with high interoperability potential
High reliability due to few moving parts
Reduced complexity and low implementation cost, critical for cost-restrained devices
Easily extensible for future needs
Applicable to all IEEE 802.3 LAN networks, may be extensible for VoWLAN
 LLDP-MED is highly applicable to a very wide range of practical
scenarios, particularly in managed enterprise networks
 Believed that all interfaces required for ECS location delivery are
defined by LLDP-MED today
 Industry accepted solution, already deployed (notably IP phones)
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References & Contacts
The formal ANSI/TIA-1057 specification is freely available for download at:
http://www.tiaonline.org/standards/technology/voip/documents/ANSI-TIA-
1057_final_for_publication.pdf
Useful links:
http://en.wikipedia.org/wiki/LLDP-MED
http://wiki.ethereal.com/LinkLayerDiscoveryProtocol
Contacts:
 Peter Blatherwick (peter.blatherwick@mitel.com); editor of ANSI/TIA-1057 (LLDPMED)
 Manfred Arndt (manfred.r.arndt@hp.com); co-author of ANSI/TIA-1057 (LLDPMED)
 Paul Congdon (paul.congdon@hp.com); project director of IEEE 802.1AB-2005
(LLDP)
and vice-chair
802.1 Working Group
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