Design of a Diversified Router: Model and System Overview

Design of a Diversified Router: Model and System Overview
Jon Turner, John DeHart, Fred Kuhns

Outline What is NOT covered in these slides JST’s original slides
Schedule Model Traffic Types IP Addressing Components Switch MetaLink Loopback Block LC Substrate Link Types Packet Formats LC Rx/Tx Design Implementation Common Router Framework (CRF) Functional Blocks for implementing a Router

Not Covered Control End Host Details about how PlanetLab works.
Installation Configuration Initialization Monitoring … End Host Substrate/Meta Model Details about how PlanetLab works. These are very important topics but for now we will talk about the Data Path in the Network.

Outline What is NOT covered in these slides JST’s original slides
Schedule Model Traffic Types IP Addressing Components Switch MetaLink Loopback Block LC Substrate Link Types Packet Formats LC Rx/Tx Design Implementation Common Router Framework (CRF) Functional Blocks for implementing a Router

compute blade with disk
System Architecture General purpose blades. shared blades run Plab OS no change to current apps also support dedicated blades use separate blade server to preserve ATCA slots for NPs NP blades. support dedicated PEs control from Vserver on PE/GP shared PE options shared NP for fast path shared NP with plugins 10 GE fabric switch VLANs used to isolate metarouters uplinks for connecting to multiple chasses Good ratio of PEs to LC: 3:1 compute blade with disk Radisys 7010 Radisys 7010 with RTM 10 GE Switch Line Card Switch Blade PE/GP PE/NP . . . up to 10 1GE interfaces 1 GE for control 10 Gb/s for data

Sharing NPs Motivation Packet flow Configuration
MRs with limited IO bandwidth can’t make full use of NP blade extreme (but perhaps common) case – 25 MRs with 100 Mb/s IO useful to allow such MRs to share a PE Packet flow ingress LC terminates external tunnel and adds internal header MR fast path determines outgoing metalink and queues packet selected packets directed to Vserver on shared GP blade injected packets placed on metalink queues in PE Configuration single NP blade hosts two shared NPs each NP engineered for 5 Gb/s throughput divide TCAM between NPs LC P L Q . . . shared NP blade S shared GP blade

Shared PE Processing code constraints finite, acyclic flow graph bounded path length restricted memory access packet buffer, control block, output area thread-safe inputs (in regs) buffer pointer output MI ctl blk pntr lookup result pntr output buffer offset use MR to find parser code and MR control block DeMux Parse Lookup ... Header Format header includes MR+MI inputs (in regs) buffer pointer MI ctl blk pntr output pntr output 16B lookup key per metalink queues with static rates input: MR+lookup key output: output MI qid (supplied by substrate) lookup result stats index Stats module not shown – inputs from DeMux, Lookup and QM. Potential for plugins using spare MEs one ME per MR, static SRAM regions,

Managing MR-Specific Data
MR control software runs on separate PE. xScale provides interface through control daemon. enable/disable MR (input packets discarded when disabled) read/write MR control block block read/writes to from memory area using offsets read/write filters substrate fills in hidden fields (MR in key, qid in result) read statistics read/write code segments cryptographic hash used to verify compliance-checking only when MR is disabled

Line Card Functions Substrate functions only Ingress Egress
terminate tunnels (VLAN, plain IP, IP tunnel, MPLS) map physical interface + tunnel id + MLI to MR+MI map MR+MI to destination blade and qid queue packets in queues with static rates (paced) provision for xScale to respond to ARP requests Egress arriving packets include MR+MI+(next-hop-metanet-adr) monitor rates for each MR/MI pair – raise alarm if threshold exceeded if MI is designated as multipoint, map next-hop-metanet-adr to MAC adr and write into blank spot in buffer if no matching entry, pass buffer pointer to ARP handler in xScale xScale handles ARP, fields reply and enqueues packet when reply received if no reply, send exception notification MR exception interface place packet in outgoing per-MI queue

Possible Extensions Queueing in shared PE Limited Plugins
allow MR to define multiple queues per MI with queue weights, per queue space allocation and per MI space allocation substrate implements fair queueing scheduler WDRR or stratified round-robin packet discarded if queue using more than its space allocation and more than its share of the shared space implement when users demand it or spare time available Limited Plugins replace Header Formatter with parallel block of MEs, one per MR code restrictions (static and run-time checks) access to restricted address ranges restricted use of bus bandwidth resources instructions inserted to increment usage counters xScale (or perhaps dedicated ME) checks counters periodically MRs using excessive bus bandwidth are disabled

Outline JST’s original slides Schedule Model Traffic Types
IP Addressing Components Switch MetaLink Loopback Block LC Substrate Link Types Packet Formats LC Rx/Tx Design Implementation Common Router Framework (CRF) Functional Blocks for implementing a Router

Schedule Two time horizons: JDD’s Proposal: techX End of Year Target:
techX Project End of 2006 Future Diversified Router Project Outstanding new grant request under which we do the rest of the work… JDD’s Proposal: techX End of Year Target: Data Path Default IPv4 MR We should be able to use N instances of this to show multiple MRs running in a Substrate Router. Legacy PlanetLab nodes in a Blade Server By Legacy we mean receiving/sending plain IP packets, no Meta/Substrate functionality present. Basic LC Substrate functionality IP Tunnel Substrate Link termination Plain IP handling MetaLink Loopback Block Control? Install an MR Configure an MR? Routing Protocols? Can this be handled through static route configuration? Etc.? End Host: Use Plain IP?

Substrate/MetaNet Model
The Substrate should provide a view to Meta Nets that their Meta Routers are directly connected via Physical Links A Meta Interface emulates a Physical Interface A Meta Link emulates a Physical Link The Substrate should provide isolation between Meta Nets Meta Net “A” MR_A MR_A MR_A MI MI MI MI MI MI Meta Net “B” MR_B MR_B MI MI MI MI Meta Net “C” MR_C MR_C MR_C MI MI MI MI MI MI

Substrate/MetaNet Model
Substrate Links connect Substrate Router Peers A Substrate Link is terminated at a Physical Interface of a Substrate Router. Meta Links connect Meta Router Peers A Meta Link is terminated at a Meta Interface on a Meta Router MetaLink 1 Substrate Link MetaLink 2 MetaLink 3 MR_A MR_A MR_A MI MI MI MI MI MI MR_B MR_B MI MI MI MI MR_C MR_C MR_C MI MI MI MI MI MI Substrate Router X Substrate Router Y Substrate Router Z

Mapping the Model onto Hardware
Meta Dedicated NP Dedicated GP Shared NP Shared GP Switch LC Loopback Substrate

Line Card Typically supports multiple Physical Interfaces Our Radisys blade when implementing a LC would have an RTM with 10 1-GE physical interfaces. Substrate Link Termination Including IP Tunnel Substrate Link termination Mux/Demux of Meta Links into/out of Substrate Links. Pass through Meta Links Plain IP Switch Substrate Switch Meta Routers on shared blades do not have a view of the switch. All switching functions are provided by the Substrate Traffic from all MRs is isolated from other MRs, including dedicated blade MRs, via the use of VLANs Meta Switch An MR on a dedicated blade has a view of a Meta-Switch including: Port its blade is on Portions of LCs that it has access to. Loopback (next slide) NP: Network Processor Blade GP: General Purpose Processing Blade

Line Card Switch Loopback Provides MRx:MIi connectivity to MRy:MIj within Substrate Router More on this later when we provide details on the components… NP: Network Processor Blade Dedicated: entire blade is dedicated to one MR. No Substrate functionality present. Shared: blade is shared among several MRs. Substrate functionality provides resource sharing and isolation GP: General Purpose Processing Blade May be realized by a blade in the ATCA chassis or in a blade server directly connected to switch blade which resides in ATCA chassis. The switch blade has front panel Ethernet interfaces (uplinks) that could be connected to the blade server for this purpose. Substrate functionality provides resource sharing and isolation.

Model: Layering and Abstractions
Two Types of Traffic Legacy MAC layer Legacy Layer (i.e. non-Substrate, typically IPv4) Substrate Substrate layer Meta layer Figures below are LAYERS, not Packet formats: Meta Substrate MAC Legacy MAC

Layer Attributes Attributes at the different layers
Physical/MAC Type: (Ethernet, ATM, …) Wireless: (1/0) Type: (P2P, MA, …) Substrate MNid MRid MLI Link Type Link Model (P2P, Multi-Access) ARP support Meta MetaLink MI MnAddr What is exposed to the MR? Type: {Ethernet, Wireless, …} P2P vs. Multi-Access ARP Provided by Substrate or Not. ???

Traffic at a Substrate Router
For now assume traffic is on wired Ethernet. Substrate: EtherType = Substrate Each frame has a Substrate Header MLI: Meta Link Identifier Identifies MR:MI to which this frame should be delivered Len Line Card: sends Meta Frame to the Blade hosting the MR indicated by the MLI includes in the Meta Header the MR’s MI that this frame is for. IP: Other:

IP: EtherType = IP Substrate Tunnels: IP Proto = Substrate Each frame has a Substrate Header immediately following IP Header MLI: Meta Link Identifier Identifies MR:MI to which this frame should be delivered Len Line Card sends Meta Frame to Blade hosting MR indicated by MLI Included in Meta Header is the MR’s MI that this frame is for. Plain IP Control Protocols: Contains no Substrate Header ICMP Substrate on LC may need to process some ICMP messages. ICMP or a subset of ICMP messages sent to XScale on LC. Depending on processing in Substrate/XScale, ICMP messages may be forwarded on to MR(s). BGP: Border Gateway Protocol (inter-domain routing protocol) Treated like Plain IP Data described below: Sent to default IP MR. OSPF: Open Shortest Path First (intra-domain routing protocol) IGMP: Internet Group Management Protocol, used for IPv4 Multicast Group membership Other? Plain IP Data: Other:

IP: Substrate Tunnels: Plain IP Control Protocols: Plain IP Data: Contains no Substrate Header Line Card forms Meta Frame and sends it to default IP MR A unique MI for the default IP MR is associated with each Physical Interface. Via the default IP MR, plain IP traffic may be destined for: Other MRs on this Substrate Router via the Loopback Other MRs on other Substrate Routers via Meta Links carried on Substrate Links The Default IP MRs on peer Substrate Routers could exchange route information so they know how to get to other Substrate Routers. Legacy (Pure IP) Planet Lab Nodes on this Substrate Router. Substrate Control Entities on XScale? Egress as Plain IP? Policy based option Other? Other: ARP:

Substrate Router(A.B.C.0 – A.B.C.255)
IP Address Assignment Substrate Router(A.B.C.0 – A.B.C.255) X.Y.Z.1 PlanetLab Blades Switch 1 U.V.W.1 2 Consider a Substrate Router (SR) with the following characteristics: 3 physical interfaces that connect to three Internet Routers: Interface 1  X.Y.Z.1 Interface 2  U.V.W.1 Interface 3  R.S.T.1 Blade server that contains 6 Legacy (Plain IP) PlanetLab Nodes A Default IPv4 MR Block of IP Addresses A.B.C.0 – A.B.C.255 R.S.T.1 3

IP Address Assignment Substrate Router(A.B.C.0 – A.B.C.255) X.Y.Z.1 A.B.C.1 PlanetLab Blades A.B.C.128 X.Y.Z.2 A.B.C.2 A.B.C.3 A.B.C.4 Switch A.B.C.5 A.B.C.6 A.B.C.7 1 U.V.W.1 A.B.C.129 U.V.W.2 2 Assign addresses to the SR as follows: Each Physical Interface has a Substrate IP Tunnel Address Interface 1  A.B.C.128 (A.B.C.0x80) Interface 2  A.B.C.129 (A.B.C.0x81) Interface 3  A.B.C.130 (A.B.C.0x82) Default IPv4 MR has 4 IP Addresses: To X.Y.Z.1 out Interface 1 : X.Y.Z.2 To U.V.W.1 out Interface 2 : U.V.W.2 To R.S.T.1 out Interface 3 : R.S.T.2 To PlanetLab Nodes: A.B.C.1 R.S.T.1 A.B.C.130 R.S.T.2 3

IP Address Assignment Substrate Router(A.B.C.0 – A.B.C.255) X.Y.Z.1 PlanetLab Blades A.B.C.1 A.B.C.128 A.B.C.2 A.B.C.3 A.B.C.4 Switch A.B.C.5 A.B.C.6 A.B.C.7 X.Y.Z.2 1 U.V.W.1 A.B.C.129 U.V.W.2 2 Route announcements: Out Interface 1 A.B.C.128/32 A.B.C.0/25 Out Interface 2 A.B.C.129/32 Out Interface 3 A.B.C.130/32 A.B.C.0.25 R.S.T.1 A.B.C.130 R.S.T.2 3

BGP Notes RFC 4271: BGP-4 BGP is defined as an inter-Autonomous System (AS) routing protocol. Autonomous System: A set of routers under a single technical administration BGP Speaker: A router that implements BGP BGP Identifier: an IP Address assigned to a BGP Speaker. Same for every local interface and BGP peer. A router may also have separate IP Addresses for its interfaces. UPDATE message used to exchange route information NEXT_HOP attribute defines IP address of the router that SHOULD be used as the next hop to the destinations listed in the UPDATE message. Would this potentially be used in ARP requests? BGP uses TCP between peers. From RFC 4271, Section 3: In the context of this document, we assume that a BGP speaker advertises to its peers only those routes that it uses itself (in this context, a BGP speaker is said to “use” a BGP route if it is the most preferred BGP route and is used in forwarding).

Switch Switch Blade Specs: Traversing the Switch: Promentum™ ATCA-2210
20-port 10GE fabric switch 14 10GE links to user slots 4 10GE links for external connections (up/cross links) on front panel 24-port 1GE Base switch 14 1GE links to users lots 1GE link to redundant switch blade 1 10GE and 4 1GE links for external connections (up/cross links) on front panel Wire-speed L2 and L3 switching 4K IEEE 802.1Q VLANs Etc… Traversing the Switch: Switching is based on Ethernet Destination Address Isolation is based on VLAN. One VLAN will be assigned to each MetaNet present on a Substrate Router. All switch traffic for a MetaNet will be required to use its assigned VLAN. Frames from a MetaNet will only be transmitted to a port which is allowed to receive the specified VLAN.

Meta Link Loopback We would like to be able to route Plain IP pkts to an MR We can achieve this by using a default IPv4 MR But we don’t want the IPv4 MR to have to know anything about other MRs and their Meta-Interfaces That is a Substrate function So, we need a Substrate function to translate from MRx:MIi to MRy:MIj We would also like to be able to route Plain IP pkts to Legacy PlanetLab Nodes residing on Blades in a Substrate Router Legacy PlanetLab Nodes have no Substrate. Again we can use the default IPv4 MR to achieve this. But the packets cannot have a Substrate Header or Meta Header when they arrive at the PlanetLab Nodes. So, we need a Substrate function to strip these headers. We would also like to be able to do similar things with IP Pkts in Substrate Frames on MetaLinks which terminate at the default IPv4 MR We will implement a Meta Link Loopback block Provides Internal Meta Link Loopbacks at the Substrate level. Probably will reside on one or more Line Cards.

Meta Link Loopback Physical interface ‘n’ Substrate Router on LC A Def
IPv4 MR n LC A m Physical interface ‘m’ on LC A MR Y n LC B Physical interface ‘n’ on LC B MR X Loopback PLab Switch

Meta Link Loopback: Plain IP to/from MR Y
Substrate Router IPAm Def IPv4 MR IP IPBn VLAN ‘a’ used. IP a n LC A Ab : MI b associated with MR A used IPYk IP Plain IP m IPAm IP MR Y Yk Plain IP n IPBn LC B Y IP MR X Loopback IPYk Yk IP Y PLab Switch

Meta Link Loopback: Plain IP to/from PLab
Substrate Router IPAm Def IPv4 MR IP IPBn VLAN ‘a’ used. IP a IPPi n LC A IP Ab : MI b associated with MR A used Plain IP m IPAm IP MR Y Plain IP n IPBn LC B IP MR X IPPi Loopback Plain IP PLab P Plain IP P Switch

Meta Link Loopback: General
IPAn Substrate Router IP IPAm Def IPv4 MR IP IPBn VLAN ‘a’ used. IP a IPPi LC A IP IPXj Ab : MI b associated with MR A used Substrate n IPAn IP IPYk IP IP Plain IP m IPAm IP MR Y Yk Plain IP n IPBn LC B Y IP MR X Xj X IPPi Loopback IP IPXj IPYk Yk Xj Y Plain IP X PLab P Plain IP P Switch

Substrate Links 2 Types of Substrate Links: Point-to-Point (P2P)
Connects two peer Substrate Routers May be realized via: Directly Connected (P2P-DC) One physical link connects an Interface on one Substrate Router to an Interface on another Substrate Router Can use VLANs or not. Tunnel (P2P-Tunnel) Two Substrate Routers have a Tunnel defined that connects an interface on each router. Such a tunnel comprises exactly one Substrate Link. Multi-Access Network (P2P-VLAN0) Substrate Routers with interfaces connected to a Multi-Access Network all use a predefined VLAN (VLAN0). VLAN0 is defined for each Multi-Access Network and my be different on each one. Each of these Substrate Routers is pre-configured with the Ethernet addresses of the other Substrate Routers connected to the Multi-Access Network. By using the Ethernet address of peers, pairs of Substrate Routers have defined Substrate Links. With N Substrate Routers, there are at most (N*(N-1))/2 Substrate Links Multi-Access

Substrate Links 2 Types of Substrate Links: Point-to-Point (P2P)
Multi-Access Supports Unicast, Multicast and Broadcast traffic from Meta Routers. Interfaces on Substrate Routers connected to a Multi-Access network are NOT necessarily pre-configured with each others Ethernet addresses. ARP may be used over the Multi-Access network to do the translation from MetaNet Address to Ethernet Address. ARP protocol and tables are managed by XScale. Can use VLANs or not, but cannot use VLAN0.

Substrate Links Substrate Link Restrictions:
P2P-DC does not co-exist on a physical interface with any of the other types of SL. P2P-Tunnel, P2P-VLAN0 and Multi-Access may all co-exist on the same physical interface. A physical interface may have: At most one P2P-DC SL XOR One or more P2P-Tunnel SLs One or more P2P-VLAN0 SLs At most one Multi-Access SLs

IP Tunnel Substrate Links
Each IP Tunnel Substrate Link is terminated at a single Physical Interface on a Substrate Router. The only route TO this end of the tunnel is from the outside into the associated physical interface. Nothing inside the Substrate Router routes TO this end of the Tunnel From inside the Substrate Router packets are just sent INTO the tunnel so they come out the other end. Included in the configuration of an IP Tunnel Substrate Link is the Address (IP or MAC?) of the next/first hop for the route to the other end of the tunnel. What happens if the routes in the Internet change and this next/first hop is no longer the way to go? Physical Interface will receive ICMP No Route to Host or ICMP Redirect messages. ICMP messages should be sent to the XScale on the Line Card. XScale should then nullify (mark as down, …) the IP Tunnel Substrate Link and all MetaLinks/MetaInterfaces associated with that Substrate Link.

IP Addressing Components Switch MetaLink Loopback Block LC Substrate Link Types Packet Formats Focus is on wired Ethernet LC Rx/Tx Design Implementation Common Router Framework (CRF) Functional Blocks for implementing a Router

Point-to-Point Directly Connected (P2P-DC)
MR LC LC MR MR MetaLinks MR P2P-DC SL Packet With VLANs Type=802.1Q (2B) MLI (2B) LEN (2B) Meta Frame TCI (2B) Type=Substrate (2B) PAD (nB) CRC (4B) DstAddr (6B) SrcAddr (6B) Without VLANs P2P should not need the Type=Substrate since it is a point-to-point physical link and should only be carrying Substrate traffic. Configuration/Policy/Implementation option?

Point-to-Point via Tunnel (P2P-Tunnel)
Substrate Link MR MR LC LC MR MetaLinks MR P2P-Tunnel SL Packet With VLANs P2P-Tunnel SL Packet Without VLANs Type=IP (2B) MLI (2B) LEN (2B) PAD (nB) CRC (4B) Meta Frame Dst Addr (4B) Src Addr (4B) Ver/HLen/Tos/Len (4B) ID/Flags/FragOff (4B) TTL (1B) Protocol=Substrate (1B) Hdr Cksum (2B) Type=802.1Q (2B) TCI ≠ VLAN0 (2B) DstAddr (6B) SrcAddr (6B) This example shows a Substrate Link in an IP tunnel over Ethernet. We could also envision other tunnel types: MPLS ATM Sonet? Etc… Ether/MAC layer encap  Tunnel Protocol Tunnel layer encap  Substrate Type=IP (2B) MLI (2B) LEN (2B) PAD (nB) CRC (4B) Meta Frame Dst Addr (4B) Src Addr (4B) Ver/HLen/Tos/Len (4B) ID/Flags/FragOff (4B) TTL (1B) Protocol=Substrate (1B) Hdr Cksum (2B) DstAddr (6B) SrcAddr (6B)

MPLS Tunnels We’ve looked at MPLS just enough to convince ourselves that we can do something, but not enough to understand all the implications. Some of the MPLS RFCs: 3031: Multiprotocol Label Switching Architecture 3032: MPLS Label Stack Encoding 3037: LDP Applicability LDP: Label Distribution Protocol 4221: Multiprotocol Label Switching (MPLS) Management Overview MPLS uses a 32-bit field which contains Label (20b) Experimental (3b) S-Bit (1b): 1 indicates bottom of label stack TTL (8b)

Point-to-Point via Multi-Access Network (P2P-VLAN0)
For this example, on each LC pictured, one interface is being used. Ethernet Switch LC MR-1 MR-2 LC MR-2 MR-1 LC MR-4 MR-2 M3 LC MR-4 MR-2 MR-3

P2P-VLAN0 Packet Format P2P-VLAN0 SL Packet (VLAN0)
Type=802.1Q (2B) MLI (2B) LEN (2B) Meta Frame TCI = VLAN0 (2B) Type=Substrate (2B) PAD (nB) CRC (4B) DstAddr (6B) SrcAddr (6B) VLAN=VLAN0 provides isolation from other traffic on the Multi-Access network.

Multi-Access One MLI used per MetaNet on a Multi-Access Substrate Link. We may want to use the MnID for the MLI for each. Ethernet Switch LC MR-1 MR-3 LC MR-3 MR-1 LC MR-2 MR-2 LC MR-1 MR-2

Multi-Access Packet Formats
SL Packet with VLANs (VLAN≠0) Multi-Access SL Packet without VLANs Type=Substrate(2B) MLI (2B) LEN (2B) DstAddr (6B) SrcAddr (6B) Meta Frame PAD (nB) CRC (4B) Type=802.1Q (2B) MLI (2B) LEN (2B) Meta Frame TCI ≠ VLAN0 (2B) Type=Substrate (2B) PAD (nB) CRC (4B) DstAddr (6B) SrcAddr (6B)

ARP for IP Packet Format
Ethernet Header Dst Addr Src Addr Type = 0x0806 (ARP) Hard Type: Type of hardware address 1  Ethernet Proto Type: Type of protocol address being mapped E.g. for IP = 0x0800 (same as EtherType for IP) Hard/Proto Size: size in bytes of address fields OP: Operation 1: ARP Request 2: ARP Reply 3: RARP Request 4: RARP Reply Sender Eth Address Sender IP Address Target Eth Address Target IP Address Type=ARP(2B) HardType=Ether (2B) ProtoType=IP (2B) DstAddr (6B) SrcAddr (6B) ARP (For IPv4) HardSize (1B) ProtoSize (1B) Op (2B) Sender Eth Addr (6B) Sender IP Addr (4B) Target Eth Addr (6B) Target IP Addr (4B)

ARP for MetaNet Multi-Access Packet Format
Ethernet Header Dst Addr Src Addr Type = 0x0806 (ARP) Hard Type: Type of hardware address 1  Ethernet Proto Type: Type of protocol address being mapped Hard/Proto Size: size in bytes of address fields OP: Operation 1: ARP Request 2: ARP Reply 3: RARP Request 4: RARP Reply Sender Eth Address Sender MetaNet Address (MNid:MnAddr) Target Eth Address Target MetaNet Address (MNid:MnAddr) Type=ARP(2B) HardType=Ether (2B) ProtoType=Substrate (2B) DstAddr (6B) SrcAddr (6B) ARP (For MN) Hard Size (1B) Proto Size (1B) Op (2B) Sender Eth Addr (6B) Sender MN Addr (nB) Target Eth Addr (6B) Target MN Addr (nB)

Other Access Technologies
ATM? Sonet? Wireless How would we characterize a wireless access network? How would we provide substrate links on a wireless network? Multi-Access network without any mechanism for isolation and differentiation of P2P and Multi-Access Links: Two possibilities: We do not support P2P on such a network We use one bit in the MLI (or one bit somewhere in some header) to indicate P2P vs. Multi-Access.

Summary: Ethernet Pkt Formats – with VLANs
P2P-Tunnel SL Pkt With VLANs Type=802.1Q (2B) MLI (2B) LEN (2B) Meta Frame TCI ≠ VLAN0 (2B) Type=IP (2B) PAD (nB) CRC (4B) DstAddr (6B) SrcAddr (6B) Dst Addr (4B) Src Addr (4B) Ver/HLen/Tos/Len (4B) ID/Flags/FragOff (4B) TTL (1B) Protocol=Substrate (1B) Hdr Cksum (2B) P2P-DC SL Pkt With VLANs Type=802.1Q (2B) MLI (2B) LEN (2B) Meta Frame TCI (2B) Type=Substrate (2B) PAD (nB) CRC (4B) DstAddr (6B) SrcAddr (6B) P2P-VLAN0 SL Pkt Type=802.1Q (2B) MLI (2B) LEN (2B) Meta Frame TCI = VLAN0 (2B) Type=Substrate (2B) PAD (nB) CRC (4B) DstAddr (6B) SrcAddr (6B) Multi-Access SL Pkt with VLANs Type=802.1Q (2B) MLI (2B) LEN (2B) Meta Frame TCI ≠ VLAN0 (2B) Type=Substrate (2B) PAD (nB) CRC (4B) DstAddr (6B) SrcAddr (6B) Ethernet Hdr Tunnel Hdr (IPv4) Substr. Hdr Meta Ethernet Trailer

Summary: Ethernet Pkt Formats – without VLANs
P2P-Tunnel SL Pkt Without VLANs P2P-DC SL Pkt Without VLANs P2P-VLAN0 SL Pkt Multi-Access SL Pkt without VLANs DstAddr (6B) DstAddr (6B) DstAddr (6B) Ethernet Hdr SrcAddr (6B) SrcAddr (6B) SrcAddr (6B) Type=IP (2B) Type=Substrate (2B) Type=Substrate (2B) Dst Addr (4B) Src Addr (4B) Ver/HLen/Tos/Len (4B) ID/Flags/FragOff (4B) TTL (1B) Protocol=Substrate (1B) Hdr Cksum (2B) MLI (2B) MLI (2B) LEN (2B) LEN (2B) Tunnel Hdr (IPv4) Meta Frame Meta Frame Substr. Hdr MLI (2B) LEN (2B) Meta Frame Meta Ethernet Trailer PAD (nB) PAD (nB) PAD (nB) CRC (4B) CRC (4B) CRC (4B)

IP Addressing Components Switch MetaLink Loopback Block LC Substrate Link Types Packet Formats LC Rx/Tx Design Implementation (Next set of slides) Common Router Framework (CRF) Functional Blocks for implementing a Router

Extra The next set of slides are for templates or extra information if needed

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Multicast Alternatives
Provide support in CRF for Multicast Allow MRs to provide code to interpret Lookup Result. Define a default Unicast format for a Lookup Result: A pure Unicast MR could use this exclusively and would not need to provide any code to interpret Lookup Result. Type bit: indicates Default format CRF Specific Data QID Stats Index MR Related Data Used by CRF MI MR Specific Data Opaque to CRF Whatever the MR developer wants… Define an MR-specific format: Type bit: indicates MR-Specific MR supplies a block of code to interpret result (next slide)

Core Components Functionality: Initialization Table management
Route/Filter tables L2 Tables MR State Table (in Demux) MetaRouter Installation/Removal

Core Components (sample App)

Core Components MetaRouter Management Core MR Specific Core
MR Code Management GP PE? MR State Tbl Mgmt MR Lookup Tbl Mgmt MR L2 Tbl Mgmt RX Core DeMux Core Parse Core Lookup Core Hdr Fmt Core QM Core TX Core Portability Framework: Core Components Infrastructure Portability Framework: Resource Manager XScale Micro- Engines Rx DeMux Parse Lookup Header Format QM Tx Code Updates Tbl Updates Init, etc.

System Configuration NumLC NumPE NumGP . . . IXP LC Blade IXP PE Blade
GE IXP PE Blade . . . GP Blade . . . Blade Server e.g. 10 GE Interfaces Per LC Switch Blades (2) NumLC + NumPE + NumGP + 2 (switch) <= 14 14 = # of slots in a full ATCA Chassis Good ratio of PEs to LCs is probably 3:1 Blade Server may take the place of the GP Blades Connected through Uplinks on Switch Blade(s)

MetaLinks Types of MetaLinks: Normal: Gateway: Pass-Through:
May be directional and asymmetric. Normal: Frames enter with a Substrate Header(MLI:LEN) and Meta Frame Frames are sent to a MetaRouter on a Processing Engine Frames leave with a Substrate Header(MLI:LEN) and Meta Frame Gateway: Frames either: Enter an interface as Legacy and get delivered to an MR as Meta Frames OR Leave an MR as Meta Frames and get sent out an interface as Legacy Pass-Through: Frames enter with a Substrate Header and Meta Frame and leave with a Substrate Header and Meta Frame without going to a MetaRouter. i.e. they go LC to LC without visiting a Processing Engine. No need for Legacy Pass-Through

MPLS Tunnels We’ve looked at MPLS just enough to convince ourselves that we can do something, but not enough to understand all the implications. Some of the MPLS RFCs: 3031: Multiprotocol Label Switching Architecture 3032: MPLS Label Stack Encoding 3037: LDP Applicability LDP: Label Distribution Protocol 4221: Multiprotocol Label Switching (MPLS) Management Overview MPLS uses a 32-bit field which contains Label (20b) Experimental (3b) S-Bit (1b): 1 indicates bottom of label stack TTL (8b) There are some special labels defined, for instance: IPv4 NULL Label: when at bottom of stack indicates that the encapsulated packet is IPv4 and should be routed as such. How would we use it? We could define a similar special label for Substrate. Our Substrate Routers would need to participate in the MPLS label distribution protocols and such. The sending Substrate Router would push the special Substrate label onto the bottom of the stack and then push the first routing label onto the stack. Packets would arrive at the receiving Substrate router interface with this bottom of stack special label that would tell us that the included packet was a substrate packet. This special label could also include the MLI and hence be a part of the Substrate header.

OLD The rest of these are old slides that should be deleted at some point.

Design of a Diversified Router: Model and System Overview

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Design of a Diversified Router: Model and System Overview

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