Post on 01-Feb-2021
(11/8/01) 802-17-01-00050, mh_brcom_03 Page 1
802.17 MAC Compatibility With 802.1D/Q
November 2001
Marc Holness, Nortel NetworksAnoop Ghanwani, Lantern Communications
Jeanne De Jaegher, AlcatelJason Fan, LuminousRobin Olsson, Vitesse
CP Fu, NEC
(11/8/01) 802-17-01-00050, mh_brcom_03 Page 2
Components of a Complete RPR ProposalTopology Discovery
Protection Switching
RPR MAC
MAC Service Definition
Media Access Control
Frame Format
Transit Path
Bandwidth Mgmt.
OAM and Layer Mgmt
Bridging
PHY interfaceEthernet
SONET/SDH
jcf_topo_0x.pdf
jal_prot_0x.pdf
am_mrm_0x.pdf
hp_bwmgnt_0x.pdf
rb_phys_0x.pdf
hp_grs_0x.pdf
cb_layer_01.pdf
mh_brcom_03.pdf
rs_frame_0x.pdf
sa_transi_0x.pdf
ib_oamp_01.pdf
(11/8/01) 802-17-01-00050, mh_brcom_03 Page 3
Objective• Satisfy the compatibility requirements as specified
in the 5 Criteria for 802.17“The Resilient Packet Ring standard will be compatible
with the relevant portions of 802.1D, 802.1Q and 802.1f”
• This proposal only demonstrates this compatibility– Not intended to mandate an implementation of bridging
for developers of 802.17
(11/8/01) 802-17-01-00050, mh_brcom_03 Page 4
Outline• 802.17 bridge reference models
• MAC requirements for compatibility with 802.1D/Q
• Operation of an 802.17 MAC within a bridge
• Transmission of bridged frames on an 802.17 MAC
• Support for ISS and E-ISS by the 802.17 MAC
• Supporting Spanning Tree Protocol
• Conclusions
(11/8/01) 802-17-01-00050, mh_brcom_03 Page 5
802.17 MAC in a Bridge• The station on the RPR is a transparent bridge and
the ring is the shared medium
Network Reference
RPR
MAC
LLC
MAC
LLC
MAC MAC
RELAY
MAC Bridge Reference
802.3802.17
(11/8/01) 802-17-01-00050, mh_brcom_03 Page 6
802.17 Bridging Reference
MAC
LLC
MAC
LLC
MAC MAC
RELAY
MAC Bridge Reference
802.3802.17
MAC MAC
RELAY
802.3
S1 S2
RPRS1 S2
Network Reference
802.17 LAN
BRIDGE
Port
Port
802.3 LAN 802.3 LAN
BRIDGE
Port
Port
Bridged Local Area Network
S1 S2
(11/8/01) 802-17-01-00050, mh_brcom_03 Page 7
802.1D/Q Assume a Broadcast Medium
• All 802 MACs operate as broadcast media• Bridging was designed to operate over broadcast media• The MAC in an 802 bridge operates in a mode that allows it
to process frames not destined to it– Referred to as promiscuous mode in the standards
• Bridging operates above the MAC– Need not be aware of protection happening at the MAC
layer• As long as a MAC can be operated as a broadcast medium,
STP, GVRP will function properly
(11/8/01) 802-17-01-00050, mh_brcom_03 Page 8
MAC Requirements for Compatibility With 802.1D/Q
• MAC must support a promiscuous mode so that it allows the Relay Entity to process packets not destined to it
• Must handle frames with all types of addresses– Unknown unicast, multicast, broadcast
• Must be able to communicate with the Bridge Protocol Entity via the LLC sublayer
• Must be able support the Internal Sublayer Service (ISS) and the Extended ISS (E-ISS) defined in 802.1D and 802.1Q respectively
(11/8/01) 802-17-01-00050, mh_brcom_03 Page 9
Operation of an 802.17 MAC in a 802.1D/Q Bridge
• The MAC must operate in promiscuous mode• All frames are “Replicated”
– The frame is “Dropped”, and– The frame is forwarded downstream if the TTL permits
Link BW Monitor entity
Link BW Monitor entity
Media AccessRate Policing Entity
Media AccessRate Policing Entity
802.17 MAC802.17 MAC
Link BW Monitor entity
Link BW Monitor entity
Media AccessRate Policing Entity
Media AccessRate Policing Entity
Link BW Monitor entity
Link BW Monitor entity
Media AccessRate Policing Entity
Media AccessRate Policing Entity
Link BW Monitor entity
Link BW Monitor entity
Media AccessRate Policing Entity
Media AccessRate Policing Entity
802.17 MAC802.17 MAC
(11/8/01) 802-17-01-00050, mh_brcom_03 Page 10
Transmission of Frames by a Bridge on an 802.17 MAC
• All packets are broadcast on the ring
• Source address stripping cannot be used since the frame may have originated from off the ring
• TTL is used to limit the scope of the packet
RPR s1
TTL= 2
TTL= 3
RPR s1
TTL= 2
TTL= 3
(11/8/01) 802-17-01-00050, mh_brcom_03 Page 11
Supporting ISS and E-ISS
LLC Entities
(Extended) Internal
Sublayer Service
(MAC method Dependent Functions)
MAC Entity
Higher Layer Entities
(Bridge Protocol Entity, Bridge Management, etc.)
MAC Relay Entity
(MAC Method Independent Functions)
LAN 1 LAN 2
(Extended) Internal
Sublayer Service
(MAC method Dependent Functions)
MAC Entity
LLC Entities
MAC ServiceMAC Service
(11/8/01) 802-17-01-00050, mh_brcom_03 Page 12
Parameters for ISS and E-ISS Service Primitives
+
+
• Frame_Type• Mac_Action• DA• SA• RI• MSDU• User-Priority• Access_Priority• FCS
• Frame_Type• Mac_Action• DA• SA• RI• MSDU• User_Priority• FCS
Transparent Bridge (802.1D)
Request
Indication
Service Primitive
• Cluster_Id
• Cluster_Id
Remote Bridge
• CFI• VLAN_Class• RIF_Info• Include_Tag
• CFI• VLAN_Id• RIF_Info
SRT (Source Route Transparent)
Source Route Bridge
VLAN Bridge (802.1Q)
(11/8/01) 802-17-01-00050, mh_brcom_03 Page 13
ISS Service Mappings for 802.17 MAC
FCS
MSDU
RPR HEADER Fields
SA
DA
MA-UNITDATA.request( frame_type, mac_action, DA, SA, Routing Information, MSDU, user_priority, access_priority, FCS)
MA-UNITDATA.indication( frame_type, mac_action, DA, SA, Routing Information, MSDU, user_priority, _____________ FCS)
Not Applicable
user_data_frame
request_with_no_response
Fixed mapping
802.17 Frame Fields
(11/8/01) 802-17-01-00050, mh_brcom_03 Page 14
E-ISS Service Mappings for 802.17 MAC
Ethernet Type
Q-Tag
FCS
MSDU
RPR HEADER Fields
SA
DA
EM-UNITDATA.request( MA-UNITDATA.request.parameters, cfi, vlan_class, rif_info, include_tag )
EM-UNITDATA.indication(MA-UNITDATA.indication.parameters, cfi, vlan_id, rif_info )
VLAN Id
VLAN assigned to frame from Ingress Rules.
Determines inclusion of tag header derived
from Egress Rules.
802.17 Frame Fields
[ Optional ]
(11/8/01) 802-17-01-00050, mh_brcom_03 Page 15
STP Interactions With 802.17
802.17 LAN (A)
Bridged Local Area Network
BRIDGE (s2)
Port
Port
BRIDGE (s3)
Port
Port
802.17 LAN (B)
BRIDGE (s1)
Port
Port
BRIDGE (s4)
Port
Port
802.3 LAN 1
BRIDGE
(s5) Port
Port
Port
802.3 LAN 3802.3 LAN 2Denotes blocking port state due to STP.
Network Reference
LAN 2 LAN 3
LAN 1
s5
s4
s3
s2s1
MAC MAC
RELAY
802.3802.17
S2
(11/8/01) 802-17-01-00050, mh_brcom_03 Page 16
ConclusionsThis Proposal: Demonstrates 802.17 MAC compatibility with 802.1D
and 802.1Q as required by the PAR and 5 Criteria.
Other Proposals:There is no other proposal that demonstrates 802.17 compatibility with 802.1D and 802.1Q.
(11/8/01) 802-17-01-00050, mh_brcom_03 Page 17
BackBack--up Chartsup Charts
(11/8/01) 802-17-01-00050, mh_brcom_03 Page 18
802.1D Reference
LLC LLC
Filter DataBase
Port State Information
Port State Information
Frame Transmit
Frame Receive
Frame Transmit
Frame Receive
Bridge Protocol Entity
Forwarding Process
LAN 1 LAN 2
• Denotes Relaying MAC frames
• Denotes reception and transmission of BPDUs
(11/8/01) 802-17-01-00050, mh_brcom_03 Page 19
802.1Q Reference
LLC LLC
Filter DataBase
Port State Information
Frame Transmit
Frame Receive
Frame Transmit
Frame Receive
Bridge Protocol Entity
Forwarding Process
LAN 1 LAN 2
• Denotes Relaying MAC frames
• Denotes reception and transmission of BPDUs
Ingress Rules
Egress Rules
Port State Information