LLDPMED Location Identification for Emergency Services Emergency Services Workshop, NY Oct 56, 2006

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LLDP-MEDLocation Identificationfor Emergency
ServicesEmergency Services Workshop, NYOct
5-6, 2006Manfred Arndt (manfred.r.arndt_at_hp.com)
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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
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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 (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

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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 (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

NENA - National Emergency Number Association PSAP
- Public Service Access Point
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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 SNMP
  and 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
  immediately in the call setup

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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

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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 802.11 SSID
• 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
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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 its 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
• 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/LinkLayerDiscoveryProtoco
  l
• Contacts
• Peter Blatherwick (peter.blatherwick_at_mitel.com)
  editor of ANSI/TIA-1057 (LLDP-MED)
• Manfred Arndt (manfred.r.arndt_at_hp.com) co-author
  of ANSI/TIA-1057 (LLDP-MED)
• Paul Congdon (paul.congdon_at_hp.com) project
  director of IEEE 802.1AB-2005 (LLDP) and
  vice-chair of IEEE 802.1 Working Group