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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 (LLDP-MED)
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LLDP-MEDLocation Identificationfor Emergency ServicesEmergency Services Workshop, NYOct 5-6, 2006Manfred Arndt (manfred.r.arndt@hp.com)
Scope • ANSI/TIA-1057 – LLDP Media Endpoint Discovery (LLDP-MED) • Extension to base IEEE 802.1AB (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) ANSI - American National Standards Institute LLDP - Link Layer Discovery Protocol TIA - Telecommunications Industry Association VoIP - Voice over IP
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 (Type, Length, Value) for: • Location identification, including to support Emergency Call Service • LAN policy discovery (VLAN, Layer 2 priority, Layer 3 QoS) • Fine grained power management for Power over Ethernet devices • Inventory management • Endpoint move detection and reporting • “Fast Start” protocol behaviour, to improve timeliness • SNMP MIBs definition to support management of above
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 (Location Configuration Information) 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 (Emergency Location Identification Number) 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 Location TLV NENA - National Emergency Number Association PSAP - Public Service Access Point
End-device based locationMethod 1 - Ideal for smart clients (e.g., SIP phones) • A management application or an LIS (Location Information Server) programs the location identification into network devices using SNMPand the LLDP-MED MIB • 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 immediatelyin the call setup
Notification based ECS (E-911)Method 2 - Infrastructure Based for smart management tools • 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
Applicability to VoWLAN • IEEE 802.11 networks are based on a shared media (per SSID) • A separate virtual link is created by AP for every station for unicast traffic • Stations share a single logical channel for broadcast/multicasts • LLDP applicability • LLDP operates above the MAC service layer, and as such can be easily implemented in any device with a MAC entity • LLDP is a multicast protocol, and as such is limited to advertise attributes common to all stations in the same 802.11SSID • Physical Location Identification • As currently defined, LLDP-MED can only provide physical location of AP • Opportunities for TLV or usage extensions to support WLAN client location discovery? AP - Access Point SSID - Service Set Identifier
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)
Summary • LLDP-MED provides several technical advantages for ECS location discovery • 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)
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 (LLDP-MED) • Manfred Arndt (manfred.r.arndt@hp.com); co-author of ANSI/TIA-1057 (LLDP-MED) • Paul Congdon (paul.congdon@hp.com); project director of IEEE 802.1AB-2005 (LLDP) and vice-chair of IEEE 802.1 Working Group