Overview of Routing Interworking Plans for Fixed

Overview of Routing & Interworking Plans for Fixed & Mobile Networks ITU-T Study Group 2 (Network & Service Operations) Question 2 (Routing) q areas of responsibility q current work in progress q interactions with IETF and ATMF q planned activities Gerald Ash, Rapporteur, Q. 2/2 Tel: +1 732 420 4578 Fax: +1 732 368 6687 Email: gash@att. com IPW-5 Rev 1 1

Areas of Responsibility q traffic routing v E. 170 (Traffic Routing) v E. 171 (International Telephone Routing Plan) v E. 350 (Dynamic Routing Interworking) v E. 352 (Routing Guidelines for Efficient Routing Methods) v E. 353 -- Routing of Calls When Using International Routing Addresses q routing across circuit-based & packet-based networks v E. 177 (B-ISDN Routing) v E. 351 (Routing of Multimedia Connections Across TDM-, ATM-, & IP-Based Networks) q mobile network routing v E. 173 (Routing Plan for Interconnection Between Public Land Mobile Networks and Fixed Terminal Networks) 2

Current Work in Progress q E. 350 -- Dynamic Routing Interworking q E. 351 -- Routing of Multimedia Connections Across TDM-, ATM-, & IP-Based Networks q E. 352 -- Routing Guidelines for Efficient Routing Methods q E. 353 -- Routing of Calls When Using International Routing Addresses 3

E. 350 -- Dynamic Routing Interworking q provides for interworking among all dynamic route selection methods v includes DNHR, RTNR, DCR, RINR, WIN, DAR, STT, DADR, ODR, & future methods v route selection method not being standardized q recommends the signaling & information-exchange parameters required to support interworking v SETUP-VDL: the via & destination switch list (VDL) parameter in the SETUP message specifies all via switches (VSs) & destination switch (DS) in path v SETUP-RES: the reservation (RES) parameter in SETUP message specifies the level of circuit reservation applied at VSs v RELEASE-CB: the crankback (CB) parameter in RELEASE message sent from VS or DS to originating switch (OS) to allow further alternate routing at OS v QUERY: provides OS to DS or OS to routing processor (RP) status request v STATUS: provides OS/VS/DS to RP or DS to OS status information v RECOM: provides RP to OS/VS/DS routing recommendation 4

E. 351 -- Routing of Multimedia Connections Across TDM-, ATM-, & IP-Based Networks q recommends established routing functionality within network type(s) for application across network types, including: q number/name translation & routing v E. 164 -NSAP based number translation/routing applied in TDM- & ATM-based networks q routing table management v automatic generation of routing tables based on network topology & status applied in TDM-, ATM- & IP-based networks v automatic update & synchronization of topology databases applied in ATM- & IPbased networks q route selection v fixed route selection applied in TDM-, ATM-, & IP-based networks v dynamic route selection (event dependent, state-dependent, time-dependent) applied in TDM-based networks q Qo. S resource management applied in TDM-based networks v bandwidth allocation & protection applied in TDM-based networks v priority routing applied in TDM-based networks v priority queuing applied in ATM- & IP-based networks 5

E. 351 -- Routing of Multimedia Connections Across TDM-, ATM-, & IP-Based Networks (Continued) q recommends the signaling & information-exchange parameters required to support the recommended routing methods, including: q number/name translation & routing v E. 164 -NSAP: address parameter in the connection setup information element (IE) for routing to destination node (DN) v INRA: international network routing address (INRA) parameter in setup IE for routing to DN v IP-ADR: IP address (IP-ADR) parameter in setup IE for routing to DN v CIC: call identification code (CIC) parameter in setup IE for routing to DN q routing table management v HELLO: parameter provides for identification of links between network nodes v TSE: topology-state-element (TSE) parameter provides for the automatic updating of nodes, links, and reachable addresses in the topology database v RQE: routing-query-element (RQE) parameter provides for the originating node (ON) to DN or ON to routing processor (RP) link- and/or node-status request v RSE: routing-status-element (RSE) parameter provides for a node to RP or DN to ON link and/or node status information v RRE: routing-recommendation-element (RRE) parameter provides for an RP to node routing recommendation 6

E. 351 -- Routing of Multimedia Connections Across TDM-, ATM-, & IP-Based Networks (Continued) q recommends the signaling & information-exchange parameters required to support the recommended routing methods, including: q route selection v DTL/ER: designated-transit-list/explicit-route (DTL/ER) parameter in the setup IE specifies each via node (VN) and the DN in the route v CBK/BNA: crankback/bandwidth-not-available (CB/BNA) parameter in the connection release IE sent from VN to ON or DN to ON; allows for possible further alternate routing at ON q Qo. S resource management v Qo. S-PAR: Qo. S parameter (Qo. S-PAR) in the setup IE includes Qo. S thresholds (e. g. , transfer delay, delay variation, packet loss) used at VN to compare link Qo. S performance to requested Qo. S threshold v TRAF-PAR: traffic-parameter (TRAF-PAR) in the setup IE (e. g. , average bit rate, maximum bit rate, minimum bit rate) used at VN to compare link characteristics to requested TRAF-PAR thresholds v Do. S: depth-of-search (Do. S) parameter in the setup IE used at VN to compare link load state to allowed Do. S threshold v MOD: modify (MOD) parameter in the setup IE used at VN to modify existing traffic parameters on an existing connection v DIFFSERV: differentiated-services (DIFFSERV) parameter is used to designate the relative priority and management policy of queues 7

E. 352 - Routing Guidelines for Efficient Routing Methods q recommends use of dynamic bandwidth reservation on shortest paths to maintain efficient bandwidth use and throughput v prevents inefficient routing under congestion which can lead to network instability and drastic throughput loss q recommends use of event-dependent routing (EDR) path selection methods to reduce flooding overhead and maintain performance v provides alternative to state-dependent routing (SDR) path selection with flooding/LSAs which can lead to large processing overheads and smaller area/AS size q illustrates use of dynamic bandwidth reservation & EDR methods q plan to extend to recommendations applicable to packet network trafficengineering/management such as MPLS/traffic-engineering 8

E. 353 - Routing Calls when Using International Network Routing Addresses q recommends an addressing plan for routing calls based on E. 164 number translation to an international network routing address v avoids work-around for using E. 164 numbers as routing addresses v avoids unnecessary allocation of E. 164 numbers for routing purposes v provides originating network identification useful for routing (e. g. , based on language of originating user) q addressing plan & formats being worked jointly with numbering question (Q 1/2) q defines an international network routing address (INRA) format v serving network translates E. 164 -> INRA v format includes a 3 -digit country code, a 5 -digit network routing address (NRA), and a 2 -digit sub-address v NRA identifies service provider network q defines a serving network identification code (SNID) format v uses same format as INRA v NRA identifies the serving network q recommends that INRA, SNID, and dialed number (DN) be carried within separate information elements in the call setup message 9

Interactions with IETF and ATMF Based on Recommendation E. 351 (Routing of Multimedia Connections Across TDM-, ATM-, and IP-Based Networks) q 5 drafts submitted to IETF q presentations made to IETF Routing Area (1), MPLS working group (2) v has led to positive discussions & collaborations with IETF routing experts v has led to bandwidth-modification & priority-routing functionality in MPLS protocol RFCs q 3 contributions submitted to ATMF q presentations made to ATMF routing/addressing & control signaling (RA/CS) working group (1), ATMF traffic management (TM) working group v has led to positive discussions & collaborations with ATMF routing experts v has led to bandwidth-modification & priority-routing functionality in UNI/PNNI/AINI protocol specifications 10

Interactions with IETF Based on Recommendation E. 351 Qo. S Resource Management q capabilities v allows integration of network services v provides automatic bandwidth allocation & protection v provides service differentiation (e. g. , priority routing services such as 800 gold & international priority routing) v queuing priority applied to achieve service differentiation q analogous methods applied in PSTNs with TDM technology over the past decade v improved performance quality & reliability v additional revenue & revenue retention v reduced operations & capital cost v allows fast feature introduction with standardized routing platform q has led to needed MPLS extensions v v 11

Interactions with IETF and ATMF Based on Recommendation E. 352 (Routing Guidelines for Efficient Routing Methods) q draft submitted to IETF q presentations made to MPLS working group (1) & trafficengineering working group (1) v has led to positive discussions & collaborations with IETF routing experts q proposed next steps v include guidelines in Traffic Engineering Framework draft v provide comprehensive informational draft on TE & Qo. S methods for multiservice networks v include guidelines in IGP TE requirements, as appropriate v use guidelines to define any needed MPLS/TE MIB objects, as appropriate 12

Planned Activities q traffic-engineering/management methods for new network applications & technologies v provide comprehensive contributions/drafts on traffic-engineering & Qo. S methods for multiservice networks v support new service applications, such as multimedia, on an integrated, shared network v support new technologies such as IMT-2000 q dynamic routing methods for new network applications & technologies v provide needed extensions to IP-, ATM-, and TDM-based capabilities to support Qo. S, performance, & other needs for new applications & technologies q intelligent network (IN) routing methods for new network applications & technologies v provide needed extensions to IP-, ATM-, and TDM-based capabilities to support IN routing capabilities for new applications & technologies 13

Planned Activities (continued) q mobile routing extensions v reflect issues such as tracking of routing address mapping of E. 164 numbers/names to IP addresses v reflect interworking of fixed, wireless, and portable terminals across various technologies, including IP-, ATM-, & TDM-based networks v complement existing recommendations on mobile system identity and global title derivation (E. 212/E. 214) q open routing application programming interface (API) v address the connection management routing parameters which need to be controlled through an applications interface 14

Backup Slides 15

Example of Multimedia Connection Across TDM-, ATM-, & IP-Based Networks IP-BASED NETWORK B b 2 b 1 TDM-BASED NETWORK A ATM-BASED NETWORK C a 2 a 1 PC c 1 a 3 c 2 LEGEND PC Switch/Router Gateway Switch/Router q need for standard routing functionality between networks (includes addressing, route selection, Qo. S resource management, signaling/information exchange) q extend established routing methods for application across network types & within TDM-, ATM, & IP-based PSTNs 16

TDM-Based Routing Experience Applicable to E. 351 q dynamic path selection v state-dependent routing (SDR), event-dependent routing (EDR), & timedependent routing (TDR) path selection widely implemented v applied in national, international, metropolitan area, & private networks v applied successfully to large fraction of PSTN traffic over past 2 decades v dynamic bandwidth reservation important for network stability v event dependent path selection (e. g. , success to the top) can be nearly as effective as state dependent path selection, but simpler v crankback very efficient in path selection & replaces need for real-time link state flooding v achieves improved performance at lower cost q Qo. S resource management v provides automatic bandwidth allocation, bandwidth protection, & priority routing v used successfully in PSTNs over the past decade 17

TDM-Based Routing Experience Applicable to E. 351 q benefits of dynamic path selection & Qo. S resource management v performance quality (reduced blocking, improved reliability, robustness to failure, reduced connection set-up delay, improved transmission quality) v service flexibility (fast feature introduction with standardized routing platform, capacity sharing among services on integrated network, new differentiated (e. g. , priority routing) services introduced) v additional revenue & revenue retention (increased call completions, reliability protects of revenue at risk, new services such as priority routing) v cost reduction (lower transmission & switching costs with advanced design, lower operations expense with automated, centralized operations, lower capacity churn, automatic routing administration) 18

IP- & ATM-Based Routing Experience Applicable to E. 351 q standards-based protocols for routing, signaling, provisioning (OSPF, BGP, MPLS, PNNI, etc. ) v signaling supports source routing with DTL/ER & crankback v signaling supports Qo. S routing functionality q network operations v automatic provisioning of links, switches, reachable addresses (with OSPF, PNNI, etc. ) v network provisioning & maintenance benefits from fewer links in sparse network topology q voice, data, multimedia service integration v achieved with IP- & ATM-based routing protocols 19

IP- & ATM-Based Routing Experience Applicable to E. 351 q network efficiency v sparse topology & flat-network routing take advantage of lower costs of hi-speed (OC 3/OC 12/OC 48) transport links & switch terminations v sparse hi-speed-link design has economic benefit (20 -30%) compared to mesh-based design q network performance v sparse hi-speed-link design has some performance benefit under overload due to full sharing of network capacity 20

Illustrative Qo. S Resource Management Method VOICE ILSR ISDN DATA VLSR WIDEBAND VOICE ISDN DATA ELSR WIDEBAND q distributed method applied on a per-virtual-network basis q ingress LSR (ILSR) allocates bandwidth to each virtual-network (VN) based on demand q for VN bandwidth increase v ILSR decides link-bandwidth-modification threshold (Pi) based on – bandwidth-in-progress (BWIP) – routing priority (key, normal, best-effort) – bandwidth allocation BWavg – first/alternate choice path v ILSR launches a CRLDP label request message with explicit route, modify-flag, traffic parameters, & threshold Pi (carried in setup priority) 21

Illustrative Qo. S Resource Management Method (continued) q via LSRs (VLSRs) keep local link state of idle link bandwidth (ILBW), including lightly loaded (LL), heavily loaded (HL), reserved (R), & busy (B) q VLSRs compare link state to Pi threshold q VLSRs send bandwidth-not-available notification message to ILSR if Pi threshold not met 22

Example for CRLSP Bandwidth Modification 23