OSPF TE Topology-Transparent Zone - PowerPoint PPT Presentation

OSPF ¡TE ¡Topology-­‑Transparent ¡Zone ¡ ¡ ¡draft-­‑chen-­‑ospf-­‑te-­‑ttz-­‑00 ¡ Huaimo ¡Chen ¡(huaimochen@huawei.com) ¡ Renwei ¡Li ¡(renweili@huawei.com) ¡ Gregory ¡Cauchie ¡(greg.cauchie@gmail.com) ¡ Alvaro ¡Retana ¡(aretana@cisco.com) ¡ Ning ¡So ¡(ningso01@gmail.com) ¡ Fengman ¡Xu(fengman.xu@verizon.com) ¡ Vic ¡Liu ¡(liuzhiheng@chinamobile.com) ¡ ¡ Mehmet ¡Toy ¡(mehmet_toy@cable.comcast.com) ¡ Lei ¡Liu ¡(liulei.kddi@gmail.com) ¡

Contents Ø Introduction to OSPF-TE TTZ Ø Extensions to OSPF Protocols v Add TTZ ID TLV into Existing TE LSA v Put Context of TE LSA into another LSA Ø Summarize TE in TTZ Ø Next Step Page 2

Introduction to OSPF-TE TTZ (virtual) between two edges with maximum bandwidth of path between them (virtual) between two edges with maximum bandwidth of path between them T3 R5 T1 R1 R6 R7 R8 T4 R2 T10 R9 R3 T3 T2 T1 T6 On a node outside of TTZ: TTZ node’s view of topology: T5 Topology with normal TE links T7 Topology with normal TE links and (i.e., topology we see on up part) TTZ TE links (i.e., topology we see T9 here in the lower part + up outside TTZ) T8 T4 T10 TTZ 100

Add TTZ ID TLV into Existing TE LSA Format of Opaque LSA for TE LSA 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | LS age | Options | LS Type=10 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 1 | Opaque ID | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Advertising Router | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | LS sequence number | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | LS checksum | length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | | ~ TLVs ~ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ TLVs: Router Address TLV (Existing) Link TLV (Existing) TTZ ID TLV (Added) TTZ Options TLV (Added into TE LSA for virtualinzing TTZ) This is simple, but it is hard to flush out LSAs for TTZ.

TTZ TLVs 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | TTZ-ID-TLV-type = 1 (TBD) | Length (4) | TTZ ID +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ TLV | TTZ ID | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | TTZ-OP-TLV-type = 4 (TBD) | Length (4) | TTZ OP +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ TLV | | | | |V| 0 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ V = 1: P2P link between two edges of TTZ for virtualizing TTZ TTZ OP TLV with V=1 added into TE LSAs for virtualizing TTZ, explicit indication

Migration to TTZ (1/2) T3 R6 T2 T1 R2 R7 T6 T7 T5 R8 T9 R3 T8 R9 T4 R10 T10 TTZ 100 1. Distribute TTZ Information: TTZ ID TLV added into TE A node outside TTZ LSAs for links in TTZ ignores TTZ ID TLV T3 R6 T2 T1 R2 R7 T6 T7 T5 R8 T9 Normal link R3 T8 R9 TTZ link T4 R10 T10 TTZ 100

Migration to TTZ (2/2) 2. Originate TE LSAs for virtualizing TTZ, and Not distribute TE LSAs for TTZ TE links to outside of TTZ TE LSAs for View topology with normal virtualizing TTZ TE links before TE LSAs for TTZ TE links aged out (e.g., see TE topology we see here) T3 R6 T2 T1 R2 R7 T6 T7 T5 R8 T9 Normal link R3 T8 R9 TTZ link T4 R10 T10 TTZ 100 Aged out TE LSAs for TE links in TTZ in nodes outside of TTZ after some time (<1 hour)

After Migration to TTZ for ~1- hour On a node outside of TTZ: Topology with normal TE links (i.e., topology we see on up part) T3 R6 T1 R2 R7 R8 Normal link R3 R9 T4 R10 T10 TTZ node’s view of topology: Topology with normal TE links and TTZ TE links (i.e., topology we see here in the lower part) T3 R6 T2 T1 R2 R7 T6 T7 T5 R8 T9 Normal link R3 T8 R9 TTZ link T4 R10 T10 TTZ 100

Put Contents of TE LSA into another LSA Format of Opaque LSA for TE TTZ 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | LS age | Options | LS Type=10 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | TTZ-LSA-type | Opaque ID | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Advertising Router | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | LS sequence number | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | LS checksum | length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | | ~ TLVs ~ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ TLVs: TTZ-LSA-type: Router Address TLV (from TE LSA) TTZ-TE-LSA-type (15?, TBD) for TTZ TE LSA Link TLV (from TE LSA) TTZ ID TLV (TTZ Options TLV added into TE LSA LSAs for normal TE LSAs of TTZ can be flushed for virtualinzing TTZ, explicit indication) out easily and quickly after migration to TTZ.

Migration to TTZ T3 R6 T2 T1 R2 R7 T6 T7 T5 R8 T9 R3 T8 R9 T4 R10 T10 TTZ 100 TTZ TE LSAs 1. TTZ TE links distributed by TTZ T3 R6 T2 TE LSA T1 R2 R7 T6 T7 T5 R8 T9 Normal link R3 T8 R9 TTZ link T4 R10 T10 TTZ 100 TE LSAs for virtualizing TTZ 2. Originate TE LSAs T3 R6 for virtualizing TTZ T2 Flushed out TE LSAs for T1 R2 R7 links in TTZ soon T6 T7 T5 R8 T9 Normal link R3 T8 R9 TTZ link T4 R10 T10 TTZ 100

After Migration to TTZ On a node outside of TTZ: Topology with normal TE links (i.e., topology we see on up part) T3 R6 T1 R2 R7 R8 Normal link R3 R9 T4 R10 T10 TTZ node’s view of topology: Topology with normal TE links and TTZ TE links (i.e., topology we see here in the lower part) T3 R6 T2 T1 R2 R7 T6 T7 T5 R8 T9 Normal link R3 T8 R9 TTZ link T4 R10 T10 TTZ 100

Summarize TE for TTZ Start SPF for finding maximum bandwidth path Initialization: candidate-list = {{root, MaxBW}}; result-tree = { }. Where for each edge node Ei, root = Ei; MaxBW is a maximum number. A1 Select node with maximum bandwidth from candidate-list as working node k; remove it from candidate-list; add it into result-tree. Yes No Is every other edge node Ej in result-tree? Maximum bandwidth from Ei to End every other edge node Ej is found. Suppose that BWk is the bandwidth of working node k (i.e., BWk is the maximum bandwidth from root to node k). For each node x connected to node k and not in result-tree, find the bandwidth BWx of node x as follows: BWx = min{BWk, BWk-x}, where BWk-x is the bandwidth of the link from node k to node x. If node x is not in candidate-list, then add {x, BWx} into candidate-list; otherwise (i.e., {x, BWx0} is in candidate-list), if BWx > BWx0, then replace {x, BWx0} in candidate-list with {x, BWx}. Page 12

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