Transcript Document 7846822

Various updates on
LLDP (IEEE 802.1AB)
and
LLDP-MED (ANSI/TIA-1057)
Peter Blatherwick
Dan Romascanu
IETF-68, IETF ECRIT / IEEE Joint Meeting
IETF-68, IETF ECRIT / IEEE Joint Meeting
1
Caveat
• This is not a formal liaison or anything like it
– Peter Blatherwick: “just a guy who happens to be Editor of LLDP-MED
(ANSI/TIA-1057)”
– Dan Romascanu: “just a guy who happens to attend IEEE 802.1”
IETF-68, IETF ECRIT / IEEE Joint Meeting
2
TIA TR-41.4 Status, LLDP-MED & ECS
•
ANSI/TIA-1057, Link Layer Discovery Protocol for Media Endpoint Devices (LLDP-MED)
–
–
–
•
TSB-146-A, IP Telephony Support for Emergency Calling Service (2nd revision)
–
–
•
Provides informational overview and possible usages of relevant technologies for device location
and other ECS needs, including LLDP-MED, DHCP-based, SNMP-based, WLAN scenarios
Publication pending
TR-41.4 liaison with NENA
–
•
Provides VoIP extensions to IEEE 802.1AB LLDP, including endpoint location (and lots more)
Published April 2006
No currently active project in TR-41.4
Responding to NENA requirements TRs (in progress)  almost all NENA location requirements
well met by LLDP-MED, some cannot be realistically met by any location method
Possible LLDP-MED extensions talked about (not committed to)
–
–
–
–
–
Ability to support location by reference and/or delivery of PIDF-LO objects directly
Ability to indicate location determination method used (manual, GPS, triangulated, etc)
Ability to indicate ECS call in progress
Possible relay/forwarding mechanisms to provide end device with LLDP-MED location,
independent of the access network mechanism in use (could be DHCP, L7 LCP, network-specific
/ proprietary …)
Support for device-specific location in WLAN environments (note: LLDP-MED supports APspecific location today)
IETF-68, IETF ECRIT / IEEE Joint Meeting
3
IEEE 802.1ABrev
•
Revision of IEEE 802.1AB – LLDP
– PAR approved November 2006
•
New information elements and a mechanism for faster exchange of
information (‘fast start’) for early exchange of capabilities
– Similar to and compatible with LLDP-MED ‘Fast Start’ (some open questions)
– Mainly to support layer 2 Congestion Management and Audio-Video Bridging
– Can also be used to push location information (same as LLDP-MED today)
•
New destination addresses and explicit forwarding rules to accurately define
the topology over transparent forwarding devices like the ones defined by
IEEE 802.1ad (provider bridges) and 802.1aj (two-port media relays – TPMR)
– Breaks the original assumption that all LLDP devices are connected on the same
media (LLDP-MED would remain single L2 link-specific)
•
Support for IEEE 802.3at (extended Power over Ethernet, “PoE Plus”)
•
Liaison with TIA TR41.4
– see http://www.ieee802.org/1/files/public/docs2007/liaison-to-tr41-4-0307.txt
IETF-68, IETF ECRIT / IEEE Joint Meeting
4
IEEE 802.3at “PoE Plus”
• IEEE 802.3at to provide higher power PoE, with management
– Many management needs aligned with LLDP-MED “Extended Power via
MDI” TLV (aka Extended PoE TLV)
– High synergy, since wired Ethernet IP Phones and other VoIP endpoints
are a large category of devices, almost all using PoE
• LLDP-MED Extended PoE TLV accepted as basis for PoE
management
– 3 proposals at March IEEE 802.3 plenary, all use LLDP-MED data
content (unclear which accepted … meeting was just last week)
IETF-68, IETF ECRIT / IEEE Joint Meeting
5
Some questions / issues for discussion
• Can IEEE 802.11 / .16 and others use LLDP-MED as the
method for location acquisition in WLAN environments ??
– IETF ECRIT currently references LLDP-MED as the single
method for location acquisition at Layer 2 (of 3 methods total)
– Yet another method at Layer 2 would be confusing, wasteful, and
add complexity (bad)
• Requirements:
– Requesting location (vs continuous update)
• What are the specific IEEE groups to work with on these
topics?
IETF-68, IETF ECRIT / IEEE Joint Meeting
6
Backup Material
IETF-68, IETF ECRIT / IEEE Joint Meeting
7
Background
• TIA TR-41.4:
– Engineering subcommittee in TIA, mandate for User Premises
Telecommunications Requirements / IP Telephony Infrastructures
• LLDP-MED (ANSI/TIA-1057):
– VoIP-specific set of extensions to LLDP (IEEE 802.1AB), created by TR41.4
– Leverages LLDP’s excellent extensibility properties
– Defines several new TLVs (Type-Length-Value) for:
–
–
–
–
LAN Policy (Diffserv, Layer 2 Priority, VLAN)
Location Identification (IETF compatible civic and geo location, plus ELIN)
Extended Power Over Ethernet
Inventory management
– Also defines some new protocol behaviour (‘Fast Start’) and a few
constrains on base LLDP
IETF-68, IETF ECRIT / IEEE Joint Meeting
8
How LLDP / LLDP-MED Works (10,000 m view)
Very simple / robust
Discovery MIB
Discovery MIB
port
device
info
A4
IP-phone
xxxx
B6
PC
xxxx
B21
Switch
xxxx
port
device
info
A19
Switch
xxxx
C2
IP-Phone
xxxx
D2
IP-Phone
xxxx
F3
IP-PBX
xxxx
I’m a
switch
I’m an
IP-PBX
I’m a
switch
I’m a
switch
I’m an
IP-Phone
PSTN
I’m a
switch
Efficient and secure
I’m a
switch
I’m a
switch
• Simple one-way periodic advertisement,
no Ack/Nak, command/response, etc.
• Frames contain formatted records
(TLVs)
• Simple time-to-live mechanism for data
aging
• “Fast Start” protocol mechanism speeds
startup and initial autoconfiguration
• Data containers defined by local and
remote MIBs (SNMP is not mandatory)
• Small number of mandatory TLVs,
several optional TLVs are defined
I’m a PC
I’m a
switch
I’m an
IP-Phone
I’m an
IP-Phone
• Transmissions contained to individual L2
links (not broadcast)
• Runs after 802.1X authentication,
preventing unauthorized access to VoIP
network
Highly extensible
• Easily defined Organization Specific
TLVs (e.g. TIA, vendor-specific, etc)
• Very clear methods to define agreed
data formats (local and remote MIB
extensions)
IETF-68, IETF ECRIT / IEEE Joint Meeting
9
LLDP-MED Content
Usage of LLDP Core Spec
All mandatory aspects of LLDP are also mandatory for LLDP-MED (chassis id, port
id, time to live, end of LLDPDU)
Mandatory formats of Chassis ID, Port ID (LLDP has several optional types)
LLDP Capabilities TLV (Telephone, embedded L2 switch, optional in LLDP)
802.3 LAN speed and duplex TLV (optional in LLDP)
802.3 PoE extended TLV (optional in LLDP)
LLDP-M ED Extensions
LLDP-MED Capabilities TLV (Device Class, TLV support)
Network Policy TLV (LAN autoconfiguration)
Mandatory
Mandatory
Madnatory for Class III
Mandatory
Not recommended
Mandatory
Mandatory
VLAN ID subtype
L2 Priority subtype
Diffserv Codepoint subtype
Location Identification TLV (supports ECS / E911 and other location services)
Mandatory for Class III
IETF Coordinate-based LCI subtype
IETF Civic Address LCI subtype
ELIN subtype (E.164 formatted dialstring, for traditional E911 support))
Extended Power over Ethernet (fine grained control and prioritization)
Inventory Management (Device manufacturer/model/sw versions etc. 7 TLVs total)
Fast Start protocol behaviour
IETF-68, IETF ECRIT / IEEE Joint Meeting
Mandatory for PoE devices
Optional
Mandatory
10