This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Carrier Ethernet with IEEE 802.1ad – Present Technology
7
• Key for customer traffic separation and network traffic engineering
• Multipoint services based on VLAN switching
• Contains broadcast functions like unknown unicast flooding and multicast/broadcast propagation
Problem : The Service Provider still has to use a customer’s MAC addresses to learn and switch traffic through their network. This causes large MAC tables in the SP core and also makes the core susceptible to DoS (purposely flooding the network with Ethernet frames to fill learning tables).
IEEE 802.1ah (PBB) is a Natural Ethernet Progression
8
B-DA(6B)
B-SA(6B)
BTAG E-type0x88a8/0x81
00(2b)
BTAG-TCI(2B)
ITAG E-type0X88e7
(2B)
ITAG-TCI(4B)
Client Data B-FCS
VID(12 bits)
DEIPCP
(3 bits)PCP
(3 bits)DEI
RES(2 bits)
I-SID(24 bits)
BTAG TCI Format ITAG TCI Format
22 Bytes
PCP – 3 bits of PriorityCFI – 1 bit Canonical
Format IndicatorDEI – 1 bit Drop Eligibility
IndicatorRES – 2 bits ReserveI-SID – 24 bits Service IndicatorC-DA – encapsulated customer DAC-SA – encapsulated customer SAVID – VLAN IdentifierTCI – Tag Control InformationFCS – Frame Check Sequence
Another VLAN, called a Backbone VLAN (or B-VID), is responsible for defining the Backbone domain. The B-VID is the “highway” all B-MACs travel on; no B-VID, no PBB connectivity.
Greater scalability is also provided using a larger Instance-Service ID, or I-SID instead of a VLAN. When a customer’s frame (with or without C-VID) or SP’s S-VID enters the PBB domain, it is assigned and equated to one of the 16.7 million available I-SIDs.
To solve the MAC address problem, (customer MAC addresses in SP network), PBB’s encapsulation method adds another level of MAC addresses to forward traffic through an Ethernet-switched network. This new level of MAC addresses, called Backbone-MACs (or B-MACs), exist and function ONLY within a PBB domain and are simply the “backbone” facing switch ports.
How PBB was chosen for the core of Next Generation Ethernet (NGE) network?
9
Technology Options for core network and metro
There is significant benefit to deploy the same technology between core and metro
• Robust network interconnection between core and metro• Monitoring and OAM capability throughout the network end-to-end • Flexible traffic management capability end to end• Ability to monitor each individual service and provide improved SLAs
How PBB Was Chosen for the Second Generation Tata Communications’ Ethernet Network?
10
There is significant benefit to deploy the same technology between core and metro
• Robust network interconnection between core and metro• Service and MAC scalability throughout the global network• Ability to monitor each individual service and provide improved SLAs • Monitoring and OAM capability throughout the network end-to-end
Time-To-Market -PBB is a mature and standardized (802.1ah) technology.-Tata Communications required a mature technology for its global network.-Tata Communications decided not to wait a few more years for other technologies to mature.
• Tata is working with vendors to develop a “thin” control plane; e.g., Shortest Path Bridging• PBB will stay as a long-term solution with multiple applications. Many vendors are working to enhance/include the
technology in their product portfolio. PBB and MPLS-TP will coexist.
• S-VLANs from access/aggregation mapped or bundled into I-SIDs on EBDs • I-SID provides service identification in PBB network• I-SIDs bundled into B-VLANs for transport over PBB core• B-VLAN defines transport topology in PBB network • Both I-SIDs and B-VLAN are statically preconfigured for traffic engineering purpose
Near term additional features• Layer 2 linear protection using G.8031• Layer 2 ring protection using G.8032• Dual homing using MC LAG• Seamless access/metro/regional/core global
network
Long term vision• Control plan• Converged transport network
34
Not all problems have a technological answer, but when they do, that is the more
• PBB is a mature technology being adopted by many equipment vendors• PBB solves many scalability issues existing on today’s equipment • PBB enhanced network security
• Tata Communications has adopted PBB for its global network to deliver better services to our customers
• More flexibility– Pick your path– Deterministic protection
• Higher quality– Monitoring the customer service independently– Nodal diversity
• Expanding service options– Burstability– Sub 10 Gig E (1,000–10,000 Meg in 500 Meg increments)– Dual local loops
35
As we go forward, I hope we’re going to continue to use technology to make really big differences in how people live
• Multipoint• Global Ethernet Market in 5 years = $40 Billion• 40% of service provider business expected to be Multipoint• PBB (802.1ah) is a multipoint technology• Is the most efficient Ethernet technology for delivering multipoint
• Scalability is greater• 16.7 Million services• 240 Gig per box
• Greatly reduced cost structure• Nodal diversity
• Layer 1• Link aggregation• MSTP/ MST-AG – contained within region
• Strong roadmap• G8031 for greater path flexibility• Service level monitoring