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CO internetworking (intra-domain + inter-layer) work in progress Malathi Veeraraghavan, Xuan Zheng, Zhanxiang Huang {mv5g, xuan, zh4c}@virginia.edu Jan. 25, 2005 1/25/2005 1 CO internetworking (intra-domain + inter-layer) • • • Terminology, questions Problem description Take a cue from CL internetworking CO internetworking CHEETAH scenario (simple) – Network-by-network setup – Continued setup • CO internetworking: complex scenarios with MPLS, VLANs, SONET, WDM • Partial CO segments intermixed with CL segments • Research problems, key ideas, conclusions 1/25/2005 Malathi Veeraraghavan, Zhanxiang Huang, Xuan Zheng {mv5g, zh4c, xuan}@virginia.edu 2 Nov. 25, 2004 Terminology • • A switch is a node in which all interfaces use the same type of multiplexing A gateway has interfaces that use different types of multiplexing Circuit based (position-based) SDM TDM WDM (space) (time) (freq.) (FSC) (TDM) (LSC) 1/25/2005 Network Internetwork Types of multiplexing Packet based (CO) • Different types of packets Connection-oriented IP (2205) VLAN (L2SC) MPLS (PSC-1) Note: there is no “CO Ethernet” multiplexing/switching 3 Legend H Host G Gateway (any type) IP IP switch: CL and CO S SONET switch 1/25/2005 V VLAN switch M MPLS switch E Ethernet switch (by default: CL) 4 Questions • Difference between LSP encoding type, switching type and GPID – Switching type: type of multiplexing used on the links of an end-to-end LSP. 3471 states “This field normally is consistent across all links of an LSP.” • e.g., TDM, PSC-1 – LSP encoding type: type of data carried on each link of the LSP 3471 says “A link may support a set of encoding formats, where support means that a link is able to carry and switch a signal of one or more of these encoding formats depending on the resource availability and capacity of the link.” 3471: “The LSP Encoding Type represents the nature of the LSP, and not the nature of the links that the LSP traverses.” MRN document says “LSP Encoding Type (representing the nature of the link that the LSP traverses)” and says on a link terminating at a gateway that can perform PSC, TDM and WDM switching, the LSP encoding is lambda. • Vijay confirmed my (and MRN) understanding that LSP encoding is below the switching level (actually all the way below) and GPID is above LSP • Examples: MPLS switch with PoS link and GbE link. For the PoS link, LSP encoding should be SONET while switching type: PSC-1 and for the GbE link, LSP encoding should be Ethernet and switching type: PSC-1. Vijay says that MPLS specs don’t allow this sort of LSP to be set up. Both switching and LSP encoding type need to be the same across a “switch” for LSP setup! – GPID: what’s carried on the LSP end-to-end 1/25/2005 5 Questions • Nested vs. contiguous vs. stitched LSPs – Tom: if you don’t treat an LSP as an FA LSP and send it out in IGP, then it may be regarded as a contiguous LSP. If there is label stacking, then it is a nested LSP. Unclear. • Plain and hybrid nodes: switch and gateway – Chris: Plain node vs. hybrid node – from mrn document – how does it relate to my “switch” and “gateway?” Plain node can also have multiple interface types (from a mux point of view) but only one mux type is enabled in a plain node at a time unlike in a hybrid node. 1/25/2005 6 CO internetworking (intra-domain + inter-layer) • • • Terminology, questions Problem description Take a cue from CL internetworking CO internetworking CHEETAH scenario (simple) – Network-by-network setup – Continued setup • CO internetworking: complex scenarios with MPLS, VLANs, SONET, WDM • Partial CO segments intermixed with CL segments • Research problems, key ideas, conclusions 1/25/2005 Malathi Veeraraghavan, Zhanxiang Huang, Xuan Zheng {mv5g, zh4c, xuan}@virginia.edu 7 Nov. 25, 2004 Initial problem • Simplistic starting point in CHEETAH – “Optical Connectivity Service” – check to see if far end has access to CHEETAH service – Added need to find MAC address of far-end host • Simplistic answer: Add “OCS available” TXT resource record to domain name in DNS server. Add MAC address associated with domain name again using TXT resource record • See example in following two slides 1/25/2005 8 A simple scenario: Ethernet-SONET-Ethernet End host 1 End host 2 SONET cloud Ethernet SONET SONET Ethernet End host 1 needs to know: • IP address of End host 2 to set up Ethernet-over-SONET circuit • MAC address of End host 2 to encapsulate Ethernet frames 1/25/2005 9 DNS based solution for determining availability of optical connectivity and MAC address If local DNS does not have the record End host 2 registers itself in local End host 1 finds End for hostend 2’shost IP address 2, it will obtain it through DNS server with “OCS available” (using query type A) and the DNS hierarchy • availability Use DNS to obtain MAC along and its address MAC address in TXT type OCS andserver MAC address High-level Resource Record (RR) with query IP address end host. (using type TXT)of far-side DNS server Local DNS server DNS hierarchy architecture End host 1 Local DNS server End host 2 SONET cloud 1/25/2005 Ethernet SONET SONET Ethernet 10 Why this approach to obtain MAC address? • • Avoid ARP broadcast going long-distance! ARP is a fine address resolution scheme if kept local – – • • For performance reasons, let’s not add another “50ms” prop. delay just for ARP Probably more important: avoid broadcast storms at Ethernet switches in both LANs DNS: natural solution for this mapping; it is already an “address resolution” server translating domain names to IP addresses. Using the DNS infrastructure to obtain MAC addresses (wide area) seems a natural extension. Implementation: – – – – 1/25/2005 RSVP-TE client at end host 1 writes an entry in the IP routing table (route add) at end host 1 showing that to reach end host 2’s second NIC IP address, next hop is the same IP address. This removes need to place remote end hosts in same subnet RSVP-TE client at end host 1 writes an entry in the ARP table mapping end host 2’s second NIC IP address to obtained MAC address Comparable to switch fabric configuration actions at a switch When an IP datagram is handed to the IP module of end host 1, it sees the destination-specific routing entry in its table and checks ARP table. It finds the MAC address and can encapsulate the IP frame with Ethernet frame and send out without requiring an ARP. 11 Initial problem description • Three problems with above simplistic solution: – Can have CHEETAH-style network islands that are not interconnected. Even if DNS query confirms “OCS available” for an end host it may not be on the same CHEETAH network as the querying host – Internetwork scenarios: the MAC address to be returned could be that of a gateway, not the far-end host – Partial CO internetworking impacts both “OCS available” and MAC issue. 1/25/2005 12 A more complex scenario: heterogeneous internetworking End host 1 End host 2 Ethernet Switch VLAN 1 Ethernet Switch Ethernet Switch MPLS router 1 MPLS router 2 Ethernet VLAN 2 Switch Ethernet 2 L3 MPLS tunnel In this case, End host 1 needs to know: • MAC address of the Ethernet interface 1 on router 1 13 1 • 1/25/2005 This should be the destination MAC address in the frames sent by End host Ethernet 1 More complete problem (in context; rather than deconstructed) • Answer four phases for operation of heterogeneous CO networks – how should topology/reachability/loading conditions be advertised through routing protocols? – how should paths be pre-computed? – what signaling parameters and values should be used in call setup (Path and Resv messages) – what are the user-plane packet formats? 1/25/2005 14 CO internetworking • Terminology, questions • Problem description Take a cue from CL internetworking • CO internetworking CHEETAH scenario (simple) – Network-by-network setup – Continued setup • CO internetworking: complex scenarios with MPLS, VLANs, SONET, WDM • Partial CO segments intermixed with CL segments • Research problems, key ideas, conclusions 1/25/2005 15 Connectionless Ethernet-IP-Ethernet Scenario ARP ARP MAC MAC Network 1 Host A H E I.1 E Switch 1 (Ethernet) Switch 2 (Ethernet) I.2 3.1 G Gateway I IP address of gateway I.1 interface End-host A’s IP routing table Internet address B II.2 IP Switch 3 (IP) Switch 3.1 interface Router A’s routing table G Gateway II B H II.3 E Switch 4 (Ethernet) Host B E Switch 5 (Ethernet) Ethernet packet-based multiplexing on all links Directly connected Router B’s routing table Network 1 address I.1 interface IP addr. I.1 interface MAC addr. 1/25/2005 3.2 IP multiplexing on all links (e.g. all PPP links) Ethernet packet-based multiplexing on all links B Network 3 Network 2 End-host A’s Internet to network address mapping table (ARP table) READ NOTES 16 CO internetworking • Terminology, questions • Problem description • Take a cue from CL internetworking CO internetworking CHEETAH scenario – Network-by-network setup – Continued setup • CO internetworking: scenarios with MPLS, VLANs, SONET, WDM • Partial CO segments intermixed with CL segments • Research problems, key ideas, conclusions 1/25/2005 17 Cheetah Scenario: Dedicated Ethernet-SONET-Dedicated Ethernet (actually SDM-TDM-SDM) Routing info distribution phases Network 1 H H1 VLSR GW2 is a gateway VLSR I.2 3.1 I.1 G 3.2 II.2 G S GW1 II.3 GW1 is a gateway H H2 GW2 SW1 (SONET) TDM muxing Internetwork: SDM muxing based network GW1’s GW1’s link link state state database database LSA originated by SW1 Sw. Cap. Link Type Sw. Cap. GW2 GW2 SW1:3.2-II.2 SW1:3.2-II.2 TDM GW:I.2-3.1 2 TDM GW2 GW2 II.3 II.3 FSC 3.2-GW2:II.2 2 TDM GW1-GW2 FSC/TDM Router Router GW2 Link Link 1/25/2005 LSA LSAoriginated originated by by GW2 GW2 Link Link GW1-GW2 II.3 SW1:3.2-II.2 Type Type Sw. Sw.Cap. Cap. Pretend 3 FSC/TDM FSC 2 18 TDM Cheetah Scenario: Dedicated Ethernet-SONET-Dedicated Ethernet (actually SDM-TDM-SDM) Path-computation phases Network 1 VLSR H H1 VLSR I.2 3.1 I.1 G GW1 3.2 S SW1 II.2 H II.3 G H2 GW2 (SONET) TDM muxing Internetwork: SDM muxing based network Outer routing table GW1’s Link State Database Dest Next hop CO type H2 GW2 SDM Router Link Sw. Cap. GW2 GW1-GW2 FSC/TDM GW2 II.3 FSC Dest Next hop CO type … GW2 SW1 TDM 1/25/2005 … … CSPF Inner routing table 19 Cheetah Scenario: Dedicated Ethernet-SONET-Dedicated Ethernet (actually SDM-TDM-SDM) Signaling phase (network-by-network setup: nested LSPs) Network 1 PATH VLSR VLSR RESV H1 H I.2 3.1 I.1 3.2 II.2 H II.3 G S G GW1 SW1 GW2 H2 (SONET) H2 GW1 TDM muxing Internetwork: SDM muxing based network READ NOTES End-host A’s CO IP routing table (consulted by RSVPTE client) Path ResvDest H2-GW2-GW1-H1 H1-GW1-GW2-H2 H2 1/25/2005 GW1-SW1-GW2GW1-SW1-GW2 GW2 BW Stack of labelsLSP enc. Sw. cap. H2 MAC Tspec (know to generate because of GPID) Intserv FSC this Fiber or Ethernet? SONET Tspec GW2 TDMMAC SONET/SDH GPID Ethertype 20 SONET/SDH Cheetah Scenario: Dedicated Ethernet-SONET-Dedicated Ethernet (actually SDM-TDM-SDM) User-plane: Data-flow phase Network 1 H2 H2 Data MAC IP H1 H VLSR VLSR SONET H2 H2 Data frameI.1MAC IPI.2 3.1 G GW1 3.2 H2 H2 Data II.2 IP II.3 MAC S SW1 G H H2 GW2 (SONET) TDM muxing Internetwork: SDM muxing based network H2 GW1 End-host A’s CO IP routing table 1/25/2005 (consulted by RSVPTE client) 21 Cheetah Scenario: Dedicated Ethernet-SONET-Dedicated Ethernet (actually SDM-TDM-SDM) (continued setup: also a nested LSP!) Network 1 PATH VLSR VLSR RESV H1 H I.2 3.1 I.1 G GW1 3.2 S SW1 II.2 II.3 G H H2 GW2 (SONET) Internetwork: SDM muxing based network H2 GW1 End-host A’s CO IP routing table (consulted by RSVP1/25/2005 TE client) Doesn’t seem to be a good solution; mismatches in crossconnect rates (e.g., lambda); gets complex if VCAT necessitates multiple LSPs READ NOTES 22 CO internetworking • • • • Terminology, questions Problem description Take a cue from CL internetworking CO internetworking CHEETAH scenario (simple) – Network-by-network setup – Continued setup CO internetworking: complex scenarios with MPLS, VLANs, SONET, WDM • Partial CO segments intermixed with CL segments • Research problems, key ideas, conclusions 1/25/2005 23 Before we start with the scenarios • Learn what current gateway implementations actually do • Some background on OSPF, OSPF-TE and GMPLS extensions • Key idea: Pretend links; allows for homogeneous LSPs to be setup in nested mode • Outermost network: SDM, VLAN, IP – Two points 1/25/2005 24 User-plane capabilities (to support CO internetworking) • Three types of gateways: – Summit Extreme • SDM ↔ VLAN (untagged ports to tagged VLANs) – Cisco GSRs • IP ↔ MPLS • VLAN ↔ MPLS • SDM ↔ VLAN (port mapped Ethernet over MPLS) – Cisco 15454/Movaz • • • • 1/25/2005 SDM ↔ SONET SDM ↔ WDM VLAN ↔ SONET? (Ethernet cards in 454)? IP ↔ SONET? (ML series cards in 454)? 25 User-plane capabilities (to support CO internetworking) • Summit Extreme – Can crossconnect SDM to VLAN – Meaning place an untagged port (port mapped) to a VLAN along with a tagged port (with a VLAN ID) – Switch is capable of popping on label (VLAN ID) and popping it off if outgoing port is untagged – The form of mux/demux on each port is changeable on a packet-by-packet basis – quite amazing! • on packet can come in w/o a VLAN tag requiring the switch to forward it according to rules of its untagged VLAN setting • another packet can come in with a VLAN tag and need to be switched accordingly. 1/25/2005 26 User-plane capabilities (to support CO internetworking) • Cisco GSR – “L3 MPLS” – map packets of a certain flow to an MPLS tunnel. – Ethernet over MPLS • VLAN • Port mapped • VLAN rewrite – This is simply a CO PS scenario where the label is changed. With a VLAN, the same label is used on all links unlike in the more generic CO PS where labels are only unique to a link – With VLAN rewrite on the other side of a different type of network, the VLAN ID is changed (i.e. label). 1/25/2005 27 User-plane capabilities (to support CO internetworking) • Cisco 15454 and Movaz box – Can map all frames arriving on a port to a SONET circuit or wavelength • SDM ↔ SONET or WDM • Unsure whether Ethernet cards are capable of processing VLAN IDs or IP header fields to then decide which ones to map to a certain SONET circuit or wavelength 1/25/2005 28 Background (what info does a switch/gateway have) • OSPF (2328): – Summary LSAs, Router LSAs, Network LSAs – Summary LSAs sent by area border routers with reachability information • OSPF-TE (3630): – TE LSAs – top-level TLV: Link TLV • ccamp extensions for GMPLS: – sub-TLVs that describe switching capability on link identified in top-level Link TLV 1/25/2005 29 OSPF-TE (3630) The following sub-TLVs of the Link TLV are defined: 1 - Link type (1 octet) 2 - Link ID (4 octets) 3 - Local interface IP address (4 octets) 4 - Remote interface IP address (4 octets) 5 - Traffic engineering metric (4 octets) 6 - Maximum bandwidth (4 octets) 7 - Maximum reservable bandwidth (4 octets) 8 - Unreserved bandwidth (32 octets) 9 - Administrative group (4 octets) 1/25/2005 30 ccamp extensions for GMPLS Sub-TLV Type Length Name 11 14 15 16 1/25/2005 8 4 variable variable Link Local/Remote Identifiers Link Protection Type Interface Switching Capability Descriptor Shared Risk Link Group 31 GSR capabilities and Link TLVs • Cisco GSR is capable of – “L3 MPLS” – mapping a flow at the IP layer to an MPLS LSP – Ethernet over MPLS: • VLAN • Port mapped • VLAN rewrite – this is nothing but changing labels – generically in CO PS networks the labels are unique only to each link; which means they are mapped from link to link on the end-to-end path. 1/25/2005 32 GSR capabilities and Link TLVs • These capabilities of the GSRs got us wondering whether in addition to Link TLVs in TE LSAs we need some way of identifying the capabilities of the gateways – e.g., whether it supports VLAN over MPLS in addition to L3 MPLS • One answer: – Don’t need another TLV – The gateways need to “pretend” they are interconnected by logical links and advertise the switching capability (i.e., the types of multiplexing) available on these links – If two LERs at the edge of an MPLS cloud can support VLAN over MPLS then they advertise a direct logical link between the LERs, which supports VLAN multiplexing 1/25/2005 33 Use routing data to ask for the right type of connection • By spreading multiplexing capabilities on these “pretend” logical links, a gateway/switch can determine whether or not there is an end-to-end path with a certain type of multiplexing • If the routing data is somehow wrong, a gateway/switch should simply reject a call if it receives a Path request for a certain type of connection that it does not support (e.g., a request for a TDM circuit via a WDM switch or a request for a VLAN connection to a gateway whose outgoing logical links to other gateways on an MPLS cloud do not support “VLAN over MPLS” 1/25/2005 34 Possible multiplexing schemes on the CO internetwork, i.e., the outermost network • Three possibilities – SDM (Fiber switch capable) – VLAN – IP (Connection-oriented) 1/25/2005 35 Two points re. outermost network • Presence of IP and Ethernet even with SDM outermost network • Forget hierarchy 1/25/2005 36 Point 1: Presence of IP and Ethernet even with SDM outermost network • Even when SDM is outermost network, user-data payload is carried in IP datagrams encapsulated in Ethernet frames – Reason 1: Use socket API in application programming – which means IP datagram encapsulation is a given. – Reason 2: Ethernet is the common NIC for end hosts; so Ethernet frame encapsulation is a given. • Small overhead – hence ignored 1/25/2005 37 Point 2: Forget hierarchy • Conventional thinking: – SDM is at the lowest level of the hierarchy – Common view: • MPLS over SONET over WDM over fiber • Contrary view here: – SDM (aka) fiber is outermost network! • Any “multiplexing/switching layer” can ride on top of any other multiplexing/switching layer – Just depends on network topology 1/25/2005 38 Scenarios • Scenario 1: SDM-(VLAN)-(MPLS)-(VLAN)SDM – No VLAN capability at end host NICs; but these NICs are connected to Ethernet switches with VLAN cap. – Gateways between VLAN and MPLS networks have VLAN capability in Ethernet cards but these gateways have no support to carry VLAN frames on MPLS LSPs • Gateways issue OSPF-TE LSAs indicating GW↔GW “pretend” links support FSC • Also basic OSPF LSAs indicate availability of “pretend” links allowing for CO IP to the outermost network (internetwork) – Make outermost network call setup be SDM 1/25/2005 39 End-to-end CO: Scenario 1 SDM-(VLAN)-(MPLS)-(VLAN)-SDM Routing info distribution phases Network 1 GW2 is a gateway VLSR Network 2 VLSR GW1 VLSR H H1 Network 3 GW2 and and GW3 are GW4 are gateway gateway s s G V G GW1 SW1 GW2 VLAN multiplexing GW1’s GW1’s Link LinkState StateDatabase Database GW1’s LSA VLSR M G SW2 GW3 MPLS multiplexing Sw. Cap. GW1-SW1 GW1-SW1 2 L2SCTDM GW2 GW2 SW1:3.2-II.2 GW1-GW2 FSC/L2SC 2 L2SC GW1-H1 GW2-GW3 3 FSC FSC/PSC-1 GW2 GW2 II.3 FSC SW1-GW2 2 L2SC 1/25/2005 GW3 GW3-GW4 FSC/L2SC V G SW3 VLAN multiplexing H2 GW4 GW2’s LSA GW2’s LSA SW1’s LSA Type Link Link Sw. Cap. Sw.Sw. Cap. Cap. Link GW3 is a gateway H Type Link Router Router VLSR VLSR Link Link Link type Type SW1-GW2 SW1-GW2 2 2 Sw.Cap. Cap. Sw. L2SC L2SC GW2-SW2 GW2-SW2 2 2 GW1-GW2 Pretend PSC-1 PSC-1 FSC/L2SC 40 GW2-GW3 FSC/PSC-1 Pretend End-to-end CO: Scenario 1 SDM-(VLAN)-(MPLS)-(VLAN)-SDM Routing path precomputation phases Network 1 VLSR Network 2 VLSR VLSR Network 3 VLSR VLSR VLSR H H H1 G V G M G GW1 SW1 GW2 SW2 GW3 VLAN multiplexing MPLS multiplexing V SW3 VLAN multiplexing G H2 GW4 Internetwork: SDM muxing based network Outer Routing table GW1’s LS database Dest. Next hop Sw. Cap. H2 GW2 FSC Router Link Link type Sw. Cap. GW2 GW1-SW1 2 L2SC GW2 GW2-SW2 2 PSC-1 GW2 GW2-GW3 Pretend FSC Dest. Next hop Sw. Cap. GW21/25/2005 GW1-GW2 … … Pretend FSC GW2 SW1 41 L2SC … … CSPF Inner Routing table End-to-end CO: Scenario 1 SDM-(VLAN)-(MPLS)-(VLAN)-SDM Signaling phase Network 1 PATH VLSR VLSR Network 2 VLSR Network 3 VLSR VLSR VLSR RESV H H H1 G V G M G GW1 SW1 GW2 SW2 GW3 VLAN multiplexing MPLS multiplexing V SW3 VLAN multiplexing G H2 GW4 Internetwork: SDM muxing based network Path Resv Dest BW Sw. Stack cap. of labels LSP enc. GPID Ethernet? of GPID) H1-GW1-GW2-GW3-GW4-H2 H1-GW1-GW2-GW3-GW4-H2 H2 Intserv H2Tspec MAC (know FSC to generateFiber thisorbecause Ethertype GW1-SW1-GW2 GW1-SW1-GW2GW2 Intserv Tspec GW2-SW2-GW3 GW2-SW2-GW3 (assumingGW3 Eth. links) Intserv Tspec 1/25/2005 GW3-SW3-GW4 GW3-SW3-GW4GW4 Intserv Tspec or packet? GW2 L2SCMACEthernet + VLAN ID VLAN? Ethertype Packet? label Ethernet? GW3 PSC-1 MAC + MPLS or packet? GW4 L2SCMACEthernet + VLAN ID VLAN? Ethertype 42 Ethertype End-to-end CO: Scenario 1 SDM-(VLAN)-(MPLS)-(VLAN)-SDM User-plane: data flow phase (MPLS network links are both Ethernet) Network 1 Network 3 Network 2 VLSR VLSR VLSR VLSR H2 H2 VLSR VLSR Data MAC IP GW3 MPLS H2 H2 GW4 VLAN H2 H2 H2 H2 GW2 Data Data Data HVLAN H2 H2 Data MAC Label MAC IP MAC 1 ID MAC IP MAC IP MAC 1 ID MAC IP H1 G V G M G GW1 SW1 GW2 SW2 GW3 VLAN multiplexing MPLS multiplexing V SW3 VLAN multiplexing G H H2 GW4 Internetwork: SDM muxing based network 1/25/2005 43 End-to-end CO: Scenario 1 SDM-(VLAN)-(MPLS)-(VLAN)-SDM User-plane: data flow phase (MPLS network links are both PPP) Network 1 Network 3 Network 2 VLSR VLSR VLSR VLSR H2 H2 VLSR VLSR Data MAC IP PPP MPLS H2 H2 GW4 VLAN H2 H2 H2 H2 GW2 Data Data Data HVLAN H2 H2 Data header Label MAC IP MAC 1 ID MAC IP MAC IP MAC 1 ID MAC IP H1 G V G M G GW1 SW1 GW2 SW2 GW3 VLAN multiplexing MPLS multiplexing V SW3 VLAN multiplexing G H H2 GW4 Internetwork: SDM muxing based network 1/25/2005 44 End-to-end CO: Scenario 1 SDM-(VLAN)-(MPLS)-(VLAN)-SDM Signaling phase MPLS network: first link is PPP and the second Ethernet Network 1 PATH VLSR Network 2 VLSR VLSR Network 3 VLSR VLSR VLSR RESV H H H1 G V G M G GW1 SW1 GW2 SW2 GW3 VLAN multiplexing MPLS multiplexing V SW3 VLAN multiplexing G H2 GW4 Internetwork: SDM muxing based network Path Resv Dest BW Stack ofLSP labels Sw. cap. enc. GPID Fiber or Ethernet? H1-GW1-GW2-GW3-GW4-H2 H2 MAC (know this because of GPID) H1-GW1-GW2-GW3-GW4-H2 H2 Intserv Tspec FSC to generate Ethertype GW1-SW1-GW2 GW1-SW1-GW2 GW2 Intserv Tspec GW2-SW2-GW3 (assuming Eth. links) GW2-SW2-GW3 GW3 Intserv Tspec 1/25/2005 GW3-SW3-GW4 GW3-SW3-GW4 GW4 Intserv Tspec Ethernet packet?ID VLAN? GW2 MAC + or VLAN L2SC Ethertype Ethernet? GW3 MAC Packet? + MPLS label PSC-1 Ethertype GW4 L2SC Ethernet packet?ID VLAN? MAC + or VLAN 45 Ethertype Scenarios contd. • Scenario 2: SDM-(VLAN-(MPLS)-VLAN)-SDM – No VLAN capability at end host NICs; but these NICs are connected to Ethernet switches with VLAN cap. – Gateways between VLAN and MPLS networks have VLAN capability in Ethernet cards and these gateways have support to carry VLAN frames on MPLS LSPs • Gateways issue OSPF-TE LSAs indicating GW↔GW “pretend” links support FSC and L2SC (VLAN) • Also basic OSPF LSAs indicate availability of “pretend” links allowing for CO IP to the outermost network (internetwork) – Make outermost network call setup be SDM 1/25/2005 46 End-to-end CO: Scenario 2 SDM-(VLAN-(MPLS)-VLAN)-SDM Routing info distribution phases Network 1 GW2 is a gateway VLSR Network 2 VLSR GW1 VLSR H H1 GW2 and and GW3 are GW4 are gateway gateway s s G V G GW1 SW1 GW2 VLAN multiplexing Network 3 VLSR GW3 is a gateway H M G SW2 GW3 MPLS multiplexing VLSR VLSR V H2 G SW3 VLAN multiplexing GW4 Internetwork: SDM muxing based network SW1’s LSA GW1’s LSA GW1’s Link State Database Link Router GW1:H1 GW4 GW2 GW1-SW1 GW2 GW4 … Link Type Link Sw. Cap. Sw. Cap. GW1-SW1 3 FSC FSC/L2SC GW1-GW4 SW1-GW2 L2SC 2 L2SC SW1-GW2 GW2-SW2 GW4:H2 PSC-1 FSC … … 1/25/2005 Link Type GW2’s LSA Sw. Cap. Type Sw. Cap. SW1-GW2 Link 2Type L2SCSw. Cap. 2 L2SC GW2-SW2 GW1-GW2 Pretend 2 PSC-1/L2SC FSC/L2SC 2 L2SC GW2-GW3 Pretend FSC/PSC-1/L2SC 47 End-to-end CO: Scenario 2 SDM-(VLAN-(MPLS)-VLAN)-SDM Routing path precomputation phases Network 1 VLSR Network 2 VLSR VLSR Network 3 VLSR VLSR VLSR H H H1 G V G M G GW1 SW1 GW2 SW2 GW3 VLAN multiplexing MPLS multiplexing V SW3 VLAN multiplexing Internetwork: SDM muxing based network GW1’s Link State Database Router Link Sw. Cap. GW4 GW1-GW4 FSC/L2SC GW4 GW4:H2 FSC GW2-GW3 FSC/L2SC/PSC-1 … … GW2 … 1/25/2005 CSPF Outer Intermediate Inner G H2 GW4 Routing tables Dest. Next hop Sw. Cap. H2 GW4 FSC Dest. Next hop Sw. Cap. GW4 GW2 L2SC Dest. Next hop GW2 SW1 Sw. Cap. 48 L2SC End-to-end CO: Scenario 2 SDM-(VLAN-(MPLS)-VLAN)-SDM Signaling phase (MPLS network links are both Ethernet) Network 1 PATH VLSR VLSR Network 2 Network 3 VLSR VLSR VLSR VLSR RESV H H H1 G V G M G GW1 SW1 GW2 SW2 GW3 VLAN multiplexing MPLS multiplexing V SW3 VLAN multiplexing G H2 GW4 Internetwork: SDM muxing based network Path Resv Dest H1-GW1-GW4-H2 H1-GW1-GW4-H2 H2 GW1-SW1-GW2-GW3-SW3-GW4 GW4 GW1-SW1-GW2-GW3-SW3-GW4 GW2-SW2-GW3 GW2-SW2-GW3 1/25/2005 GW3 BW Sw. caps LSP enc. Stack of labels GPID Intserv Tspec FSC Fiber of GPID) Ethertype H2 MAC (know to generate this because ? L2SC + VLAN ID ? GW2 MAC Ethertype IntservGW3 TspecMAC +PSC-1 Packetlabel Ethertype VLAN ID +MPLS 49 End-to-end CO: Scenario 2 SDM-(VLAN-(MPLS)-VLAN)-SDM User-plane: data flow phase (MPLS network links are both Ethernet) Network 1 Network 3 Network 2 VLSR VLSR VLSR VLSR H2 H2 VLSR VLSR Data MAC IP GW3 MPLSVLAN H2 H2 GW4 VLAN H2 H2 GW2 Data H2 H2 Data HVLAN H2 H2MAC Data Label 1 ID MAC IP Data MAC 1 ID MAC IP MAC 1 ID MAC IP MAC IP H1 G V G M G GW1 SW1 GW2 SW2 GW3 VLAN multiplexing MPLS multiplexing V SW3 VLAN multiplexing G H H2 GW4 Internetwork: SDM muxing based network 1/25/2005 50 Scenarios contd. • Scenario 3: VLAN-(MPLS)-VLAN – VLAN capability at end host NICs and these NICs are connected to Ethernet switches with VLAN cap. – Gateways between VLAN and MPLS networks have VLAN capability in Ethernet cards and these gateways have support to carry VLAN frames on MPLS LSPs • Gateways issue OSPF-TE LSAs indicating GW↔GW “pretend” links support FSC and L2SC (VLAN) • Also basic OSPF LSAs indicate availability of “pretend” links allowing for CO IP to the outermost network (internetwork) – Make outermost network call setup be VLAN 1/25/2005 51 End-to-end CO: Scenario 3 VLAN-(MPLS)-VLAN Routing info distribution phases Network 2 VLSR VLSR GW3 is VLSR GW2 is VLSR VLSR a gateway H VLSR a gateway H1 H V V G M G V V SW1 SW2 GW2 SW3 GW3 SW4 SW5 H2 MPLS multiplexing VLAN multiplexing GW2’s GW2’s Link LSA State Database GW2’s Link State Database Type Sw. Cap. GW2-SW3 GW3 SW3-GW3 2 PSC-1 PSC-1GW2-SW3 GW3 GW2-GW3 FSC/L2SC/PSC-1 2 PSC-1 GW2’s LSA LSA GW2’s Link Type Link Type Sw. Sw.Cap. Cap. SW3-GW3 22 PSC-1 SW3-GW3 PSC-1 SW2-GW2 GW3 GW3-SW4 2 L2SC L2SC SW3-GW3 GW3 GW3-SW4 L2SC 2 PSC-1 GW3-SW4 GW3-SW4 22 GW2-GW3 Pretend Router Link Router Type Link Sw.Sw. Cap.Cap. Link Link Sw. Cap. 1/25/2005 … … GW2’s LSA … … …… L2SC 52 L2SC L2SC End-to-end CO: Scenario 3 VLAN-(MPLS)-VLAN Routing path precomputation phases Network 2 VLSR VLSR VLSR VLSR VLSR VLSR H H H1 V G M G V SW3 GW3 V SW2 GW2 SW4 SW5 V SW1 H2 MPLS multiplexing VLAN multiplexing GW2’s Link State Database Router Link Sw. Cap. GW3 GW2-GW3 FSC/L2SC/PSC-1 GW3 GW3-SW4 L2SC … … … 1/25/2005 CSPF Outer Inner Routing tables Dest. Next hop Sw. Cap. H2 GW3 FSC Dest. Next hop GW3 SW3 Sw. Cap. 53PSC-1 End-to-end CO: Scenario 3 VLAN-(MPLS)-VLAN Signaling phase (MPLS network links are both Ethernet) Network 2 PATH VLSR VLSR VLSR VLSR VLSR VLSR RESV H H H1 V V G M G V V SW1 SW2 GW2 SW3 GW3 SW4 SW5 H2 MPLS multiplexing VLAN multiplexing Path Resv Dest BW H1-SW1-SW2-GW2-GW3-SW4-GW4H1-SW1-SW2-GW2-GW3H2 SW4-GW4-H2 H2 GW2-SW3-GW3 GW2-SW3-GW3 GW3 1/25/2005 Sw.Stack caps of labels LSP enc. GPID to generate this because of Ethertype GPID) ?H2 MAC (know L2SC ? Intserv Tspec GW3 MAC + VLAN ID PSC-1 Packet Ethertype 54 End-to-end CO: Scenario 3 VLAN-(MPLS)-VLAN Signaling phase (MPLS network links are both Ethernet) Network 2 VLSR GW2 VLAN H2 H2 Data MAC 1 ID MAC IP H VLSR SW1 VLSR VLSR VLSR GW3 MPLSVLAN H2 H2 H2 VLAN H2 H2 Data Data MAC Label 1 ID MAC IP MAC 1 ID MAC IP H1 V VLSR H V G M G V SW3 GW3 V SW2 GW2 SW4 SW5 H2 MPLS multiplexing VLAN multiplexing 1/25/2005 55 Scenarios contd. • Scenario 4: VLAN-(SONET)-VLAN – VLAN capability at end host NICs and these NICs are connected to Ethernet switches with VLAN cap. – Gateways between VLAN and SONET networks have VLAN capability in Ethernet cards and these gateways have support to carry VLAN frames on SONET circuits • Gateways issue OSPF-TE LSAs indicating GW↔GW “pretend” links support FSC and L2SC (VLAN) • Also basic OSPF LSAs indicate availability of “pretend” links allowing for CO IP to the outermost network (internetwork) – Make outermost network call setup be VLAN – See notes 1/25/2005 56 End-to-end CO: Scenario 4 VLAN-(SONET)-VLAN Routing info distribution phases Network 2 VLSR VLSR GW3 is VLSR a gateway H VLSR GW2 is VLSR VLSR a gateway H1 H H2 V V G M G V V SW1 SW2 GW2 SW3 GW3 SW4 SW5 SONET multiplexing VLAN multiplexing GW2’s GW2’s GW2’s Link Link LSA State State Database Database Router Router Link GW2’s LSA Type Link Link Sw. Cap. Sw.Sw. Cap.Cap. Link GW2’s GW2’sLSA LSA Type Sw. Cap. Link GW2-SW3 GW3 GW3 SW3-GW3 GW2-GW3 2 TDM TDM FSC/TDM GW2-SW3 2 TDM SW3-GW3 22 SW2-GW2 GW3 GW3 GW3-SW4 GW3-SW4 2 L2SC L2SC L2SC SW3-GW3 2 TDM GW3-SW4 22 1/25/2005 … … … … …… GW2-GW3 Type Type Sw.Sw. Cap. Cap. Pretend TDM TDM L2SC L2SC 57 FSC/TDM End-to-end CO: Scenario 4 VLAN-(SONET)-VLAN Routing protocol and path precomputation phases Network 2 VLSR VLSR VLSR VLSR VLSR VLSR H H H1 V G M G V SW3 GW3 V SW2 GW2 SW4 SW5 V SW1 H2 SONET multiplexing VLAN multiplexing GW2’s Link State Database Router Link Sw. Cap. GW3 GW2-GW3 FSC/TDM GW3 GW3-SW4 L2SC … … … 1/25/2005 CSPF Outer Inner Routing tables Dest. Next hop Sw. Cap. H2 GW3 FSC Dest. Next hop GW3 SW3 Sw. Cap. 58TDM End-to-end CO: Scenario 4 VLAN-(SONET)-VLAN Signaling phase Network 2 PATH VLSR VLSR VLSR VLSR VLSR VLSR RESV H H H1 V V G S G V V SW1 SW2 GW2 SW3 GW3 SW4 SW5 H2 SONET multiplexing VLAN multiplexing Path Dest Resv BW H1-SW1-SW2-GW2H2 ? H1-SW1-SW2-GW2-GW3-SW4GW3-SW4-GW4-H2 GW4-H2 GW2-SW3-GW3 GW3 GW2-SW3-GW3 1/25/2005 Sw. Stack caps of labels LSP enc. GPID L2SC to generate this ? because of Ethertype H2 MAC (know GPID) SONET Tspec GW3TDM SONET/SDH SONET label + VLAN ID SONET/SDH 59 End-to-end CO: Scenario 4 VLAN-(SONET)-VLAN User-plane: data flow phase Network 2 VLSR VLSR VLSR VLSR GW2 VLAN H2 VLSR H2 Data MAC 1 ID MAC IP SONETVLAN H2 H2 H2 VLAN H2 H2 Data Data H frame 1 ID MAC IP MAC 1 ID MAC IP H1 V V G SW1 SW2 GW2 VLAN multiplexing 1/25/2005 S G SW3 GW3 SONET multiplexing V SW4 VLAN multiplexing VLSR H H2 V SW5 60 For each scenario, answer the following questions 1. Routing protocol and path pre-computation phase: • 2. What should have been advertised by OSPF-TE and what computations should have been run by CSPF modules? Signaling phase: • What types of objects are used in Path messages for the five parameters and what values are set in the key fields of these objects? What labels are carried in the Resv messages? Which interface’s MAC address is necessary at sender? • 3. User-plane: • 1/25/2005 Packet formats on each interface 61 Why end host needs CO reachability information with type of CO service (slide i) • In CL IP networks: – default setting: use IP subnet address to determine whether destination is directly reachable or not? – this allows sending end host to issue an ARP with IP address of destination host or IP address of gateway (typically just one – since there is only one type of internetwork CL service, aka IP) 1/25/2005 62 Why end host needs CO reachability information with type of CO service (slide ii) • If the sending host has a manually set entry in its IP routing table for the destination host which is on a different subnet as well as an entry in the ARP table giving the MAC address of the destination (H2) – It can generate a frame with destination MAC address = H2 and destination IP address = H2 – The default gateway will not intercept the packet in some sort of proxy mode and relay it to the destination – This is an application of the “end-to-end argument” – If the gateway did intercept such a packet, it becomes more like Intelligent Networks – What will happen is that the default gateway will not accept the packet since the destination MAC address does not match it’s own interface’s MAC address. Therefore the packet will just be dropped 1/25/2005 63 Why end host needs CO reachability information with type of CO service (slide iii) • Applying similar reasoning – it is the responsibility of the end host to generate a Path message requesting the “right” type of connection to a destination, i.e., one that is indeed available. – if such a connection is not possible, the call should be rejected • Sending end host has three options for the type of connection it can request – SDM – VLAN – CO IP 1/25/2005 64 Why end host needs CO reachability information with type of CO service (slide iv) • This concept of the gateway not automatically changing the type of Path request holds at each hop. • Example: – In scenario 1, if the VLAN-MPLS GW2 had not announced availability of SDM multiplexing on its pretend link to the far-end GW on the MPLS network, the SDM-VLAN GW1 would not have issued the Path request of the SDM variety. – By having OSPF-TE LSAs for pretend links, we can use the endto-end argument in CO networks – Without these LSAs, gateways would need to automatically convert the type of requests – makes it more IN like. 1/25/2005 65 Why end host needs CO reachability information with type of CO service (slide v) • Implication – End hosts need to keep a CO routing table – How is this information learned at end hosts – LMP? Since end hosts don’t run OSPF Destination IP addr (subnet or host) 1/25/2005 Gateway (next-hop) Type of connection (SDM, VLAN, CO IP) 66 CO internetworking • • • • Terminology, questions Problem description Take a cue from CL internetworking CO internetworking CHEETAH scenario (simple) – Network-by-network setup – Continued setup • CO internetworking: complex scenarios with MPLS, VLANs, SONET, WDM Partial CO segments intermixed with CL segments • Research problems, key ideas, conclusions 1/25/2005 67 Partial Connection Oriented: Scenario 1 Ethernet-MPLS-Ethernet Scenario Routing protocol and path precomputation phases VLSR H1 H I.1 E E Network 3 Network 2 Network 1 I.2 VLSR 3.1 G GW1 Ethernet packet-based multiplexing (E1) 3.2 II.2 M G SW3 (MPLS) H II.3 E GW2 E H2 Ethernet packet-based multiplexing (E2) IP packet-based multiplexing H2 GW1 End-host A’s routing table 1/25/2005 Link Sw. Cap. Link Sw. Cap. GW1-GW2 PSC-1 GW1-GW2 PSC-1 GW2’s advertised link TLVs GW3’s advertised link TLVs 68 Partial Connection Oriented: Scenario 1 Ethernet-MPLS-Ethernet Scenario Signaling phase PATH VLSR tagging H1 Network 3 Network 2 Network 1 VLSR untagging RESV H I.1 E E I.2 G GW1 Ethernet packet-based multiplexing (E1) 3.1 3.2 M SW3 (MPLS) II.2 H II.3 G GW2 E E H2 Ethernet packet-based multiplexing (E2) Ethernet packet-based multiplexing H2 GW1 End-host A’s routing table Path Resv Dest H1-GW1-GW2-H2 H1-SW2-GW2-H2 H2 1/25/2005 GW2-SW3-GW3 GW1-SW3-GW2 GW3 BW Stack Sw. capsof labels LSP enc. GPID H2 MAC to generate this Packet because of GPID) Intserv Tspec (knowPSC-1 Ethertype Intserv Tspec GW2 MAC + MPLSPacket label PSC-1 69 Ethertype Partial Connection Oriented: Scenario 1 Ethernet-MPLS-Ethernet Scenario User-plane: data flow phase (MPLS network links are both Ethernet) VLSR GW1 H2 Data MAC IP H1 I.1 E E Ethernet packet-based multiplexing (E1) 1/25/2005 VLSR GW2 MPLS H2 Data MAC Label IP I.2 3.1 H Network 3 Network 2 Network 1 G GW1 3.2 M SW3 (MPLS) H2 H2 Data II.2 MAC IP II.3 G GW2 H E E H2 Ethernet packet-based multiplexing (E2) 70 Partial Connection Oriented: Scenario 2 Ethernet-SONET-Ethernet Scenario Routing protocol and path precomputation phases Network 3 Network 2 Network 1 VLSR H1 H I.1 E E I.2 VLSR 3.1 G GW1 Ethernet packet-based multiplexing (E1) 3.2 II.2 M G SW3 (SONET) H II.3 E GW2 E H2 Ethernet packet-based multiplexing (E2) Ethernet packet-based multiplexing H2 GW1 End-host A’s routing table 1/25/2005 Link Sw. Cap. Link Sw. Cap. GW1-GW2 TDM GW1-GW2 TDM GW2’s advertised link TLVs GW3’s advertised link TLVs 71 Partial Connection Oriented: Scenario 2 Ethernet-SONET-Ethernet Scenario Signaling phase PATH VLSR tagging H1 Network 3 Network 2 Network 1 VLSR untagging RESV H I.1 E E I.2 G GW1 Ethernet packet-based multiplexing (E1) 3.1 3.2 M SW3 (SONET) II.2 H II.3 G GW2 E E H2 Ethernet packet-based multiplexing (E2) Ethernet packet-based multiplexing H2 GW1 End-host A’s routing table Path Resv Dest H1-GW1-GW2-H2 H1-SW2-GW2-H2 H2 1/25/2005 GW1-SW3-GW2 GW1-SW3-GW2 GW3 BW Stack Sw. capsof labels LSP enc. GPID H2 MAC to generate this Packet because of GPID) Intserv Tspec (knowPSC-1 Ethertype SONET Tspec GW2 label TDMSONETSONET/SDH 72 SONET/SDH Partial Connection Oriented: Scenario 2 Ethernet-SONET-Ethernet Scenario User-plane: data flow phase VLSR GW1 H2 Data MAC IP H1 I.1 E E Ethernet packet-based multiplexing (E1) 1/25/2005 VLSR SONET H2 H2 Data frame MAC IP I.2 3.1 H Network 3 Network 2 Network 1 G GW1 3.2 M SW3 (MPLS) H2 H2 Data II.2 MAC IP II.3 G GW2 H E E H2 Ethernet packet-based multiplexing (E2) 73 CO internetworking (intra-domain + inter-layer) • • • • Terminology, questions Problem description Take a cue from CL internetworking CO internetworking CHEETAH scenario (simple) – Network-by-network setup – Continued setup • CO internetworking: complex scenarios with MPLS, VLANs, SONET, WDM • Partial CO segments intermixed with CL segments Research problems, key ideas, conclusions 1/25/2005 Malathi Veeraraghavan, Zhanxiang Huang, Xuan Zheng {mv5g, zh4c, xuan}@virginia.edu 74 Nov. 25, 2004 Research vs. eng. problems • Problem statement – How to create connections (rate-guaranteed allocations) across CO networks that support different types of multiplexing? • Mostly engineering problems – What type of Path message objects to use, and what values to use for the fields in these objects? – How to declare “pretend” links to allow for path computation or next-hop 1/25/2005 75 “Pretend” links G GW2 G SW3 SW2 Path GW3 SW4 M M M G GW1 OSPF • M M SW1 MPLS mux. SW5 G G GW4 GW5 How many pretend links should be advertised to outside this network? – N(N-1)/2 links, where N is number of GWs, e.g.,GW1↔GW2; GW1↔GW3..... • What is the capacity for each of these pretend links? How should gateway-to-switch and switch-to-switch link capacity be divided between the pretend links before advertising – estimates? • Actual routing of connections to make these pretend links real can be changed during setup. • Switching capabilities on these links are easy – if GW1 supports VLAN over MPLS as well as Layer 3 MPLS, just advertise 1/25/2005 76 L2SC, SDM and whatever allows for 2205 RSVP (which is CO IP) Is there a research problem? • First consider the research problems in this whole area of routing/signaling/user-plane protocols – in homogeneous networks – There are two problems when deconstructed (i.e, context is removed) 1. 2. 1/25/2005 routing problem deconstructs to the constrained shortest path computation in a graph problem signaling – main aspect is bandwidth management – CAC; so here the research problem is how to bandwidth share? Accept/reject a call or provide less BW than asked for? Classes of service; fairness traded off against utilization; ULGM sharing; how to set UL and GMs? 77 CSPF routing deconstructed problem in homogeneous network Link weight Available BW 2, 30Mbps a b 1, 150Mbps d 5, 100Mbps 2, 50Mbps c • • • • 1, 10Mbps f 1, 500Mbps 1, 50Mbps 1, 50Mbps e Example constraint: bandwidth Problem: find SP from a-f with min. BW = 30Mbps Answer: a-b-c-e-f: path weight = 2 + 5 + 1 + 1 = 9 Path a-b-d-f is shortest path with path weight = 2+1+1 = 4, but BW available is only 1/25/2005 78 10Mbps, less than the required 30Mbps How does the addition of the heterogeneity dimension affect these two research problems? Routing problem Available BW Crossconnect granularity e.g., WDM switch 1Mbps Link weight 1, 3200Gbps 2, 30Mbps b 10Gbps 1, 8000Gbps a d 5, 100Mbps f 1, 10Gbps 2, 10Gbps 1, 10Gbps e.g., SONET switch e c 1Mbps e.g., MPLS switch • • • 1, 2.5Gbps • • 51Mbps New constraint: node crossconnect granularity Problem: find SP from a-f with min. BW = 30Mbps Answer: a-b-d-f: path weight = 2 + 1 + 1 = 4, and 30Mbps is available, but it needs the setup of a 10Gbps circuit on b-d-f before 30Mbps can be assigned on this logical link. If1/25/2005 the rule had been to tie up minimum extra bandwidth, then path would be a-b-c-e-f 79 Or split connection on small-granularity paths Bandwidth sharing deconstructed problem in homogeneous network Request for 30Mbps connection 2, 30Mbps a b 1, 150Mbps d 5, 100Mbps 2, 50Mbps c 1, 10Mbps f 1, 500Mbps 1, 50Mbps 1, 50Mbps e • Problem: Should node b accept the call, reject the call or assign it some BW lower than the requested 30Mbps – Simple Complete Sharing (CS) algorithm would say yes! – But from a fairness perspective (short-duration vs. long-duration, short-path vs. long-path), node b may reject the call or give a lower BW level 1/25/2005 • Added dimension: to split call on different routes 80 Bandwidth sharing deconstructed problem in heterogeneous network Request for 30Mbps connection 1Mbps 2, 30Mbps a b 1, 150Mbps 10Gbps d 5, 100Mbps 2, 50Mbps c 1, 10Mbps 1, 50Mbps f 1, 500Mbps 1, 50Mbps e 51Mbps 1Mbps • Problem: – Tradeoff of fairness and utilization becomes more difficult when these crossconnect granularities are 1/25/2005 considered 81 Hop-by-hop vs. source routing • I think both can be supported even for QoSbased routing • Industry seems to lean toward source routing 1/25/2005 82 Key ideas • Use nested LSPs, each of a uniform multiplexing type (aka switching capability) • Advertise “pretend links” to enable other gateways/switches to determine whether they can set up an LSP of a certain type 1/25/2005 83 Conclusions • Is there a protocol to share reachability data from nearest CO switch/gateway to end host – use of LMP? • Pretend links – how do nodes automatically recognize need to report these? – From OSPF-TE LSAs on interface switching capabilities, easy to recognize gateways from switches – A gateway reports a pretend link to each other gateway that it can reach with one form of multiplexing – Report current available BW as minimum available BW to each gateway (ignore the fact that if a connection got set up to one gateway, the available BWs drop and hence available BW to another gateway will also drop) 1/25/2005 84 Conclusions for my original problem • What should OCS do? – Useful to bring back MAC address of destination end host? – Determine type of CO path available? 1/25/2005 85 What software modules need to be developed and deployed e.g., SDM-(VLAN)-(MPLS)-(VLAN)-SDM Serves as an RSVP-TE client at an “end host” for this connection OSPF LSA Pretend link advertiser PATH H Pretend link advertiser Network 1 Pretend link signaling module Pretend link signaling module VLAN VLSR VLAN VLSR G V OSPF-TE H1 GW1 Network 2 RSVP-TE Pretend link advertiser Pretend link signaling module Network 3 VLSR VLAN multiplexing Cisco GSR Pretend link signaling module Update conn. table RESV H OSPF-TE M RSVP-TE V SW2 SW1 Pretend link advertiser SW3 MPLS multiplexing GW3 VLAN multiplexing G H2 GW4 Internetwork: SDM muxing based network Identify what functionality each gateway box and custom-build gateway GMPLS engine for that box. Leverage software 1/25/2005in box. implemented See next slide for functional description of pretend link advertiser and pretend link signaling module. A Cisco GSR has • RSVP-TE software as an end client, i.e., an MPLS LER • RSVP-TE 86 Software for gateways • • Pretend link advertiser:one per gateway - reads OSPF-TE database, recognize from interfaces on all switches in network 2 that node GW3 is a gateway (links with multiple switching capabilities); this means a pretend link should be advertised between these two gateways. Determine what switching capabilities and rates to advertise for this pretend link based on user-plane gateway capabilities of the box. The pretend links should not be written into the connectivity table of the nodes unless there is software in the nodes to handle these links differently from regular links. Pretend-link signaling module: one per-gateway; if gateway has no RSVP-TE LER (edge) engine to act like an end host client RSVP-TE, then it serves this functionality for the gateway. If the gateway does have this built-in functionality, it simply serves to hold up Path messages headed for the pretend links and invoke the RSVP-TE client software through a CLI/TL1 command to initiate call setup. Thus, it receives RSVP-TE messages, determines if it requires pretend link setup, then issues commands to initiate the set up of the pretend link if not already setup. Then if the box has ability to integrate the newly setup LSP as a FA -LSP, then it transparently passes the SDM RSVP-TE path setup message to the RSVP-TE signaling module built into the gateway. The latter will make the GW2 RSVP-TE signaling module handle it and send one to the GW3 RSVPTE signaling module; these modules act as the RSVP-TE end host clients for the intranetwork connection or as the external trigger for the RSVP-TE client built into the node as an end host client (e.g., the GSR). 1/25/2005 87 End host first CO node discovery • Define a protocol for end host software to broadcast a discover – see if DHCP can be used augmented with usage of some obscure field. • Get multiple replies of which nodes have CO capability. • Copy routing data from these nodes to know which IP addresses are reachable through what form of CO network: SDM, VLAN or IP. • Need to deploy end host software for this purpose as well as software external to CO nodes to respond to end hosts queries. • Limit this to an enterprise. If enterprise doesn’t purchase CO service, individual end hosts cannot. So the DHCP discovery of CO capability only spreads up to the WAN access router. 1/25/2005 88 MAC address software? • If sending RSVP-TE client at end host asks for SDM or VLAN call with GPID as Ethernet, then receiving RSVPTE client at end host responds with MAC address of itself in stacked label. – Question: can Resv message processing at switches simply pass this along? • If sending RSVP-TE client at end host asks for CO IP call (2205), then do not return MAC address. • Software needed only at end hosts to handle MAC issue, provided intermediate switches simply pass on higher levels of label stacks. • Test with SN16000 and Cisco GSR. 1/25/2005 89 • Test RSVP 2205 set up with GSR.