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Contents
Ø Introduction to OSPF-TE TTZ v Add TTZ ID TLV into Existing TE LSA Ø Extensions to OSPF Protocols v Put Context of TE LSA into another LSA Ø Summarize TE in TTZ Ø Next Step
OSPF TE Topology-Transparent Zone - - PowerPoint PPT Presentation
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
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SLIDE 3
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
R5 R6 R7 R9 R8 R3 R1 R2
T4 T2 T5 T8 T3 T9 T10 T1 T7 T6
TTZ 100
T4 T3 T10 T1
On a node outside of TTZ: Topology with normal TE links (i.e., topology we see on up part) 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 + up outside TTZ)
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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.
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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 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ TTZ ID TLV 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) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | | | | |V| 0 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ TTZ OP TLV 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
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Migration to TTZ (1/2)
R6 R7 R8 R10 R9 R2 R3
T4 T2 T5 T8 T3 T9 T10 T1 T7 T6
TTZ 100
Normal link TTZ link R6 R7 R8 R10 R9 R2 R3
T4 T2 T5 T8 T3 T9 T10 T1 T7 T6
TTZ 100
- 1. Distribute TTZ Information:
TTZ ID TLV added into TE LSAs for links in TTZ A node outside TTZ ignores TTZ ID TLV
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Migration to TTZ (2/2)
TE LSAs for virtualizing TTZ View topology with normal TE links before TE LSAs for TTZ TE links aged out (e.g., see TE topology we see here) Aged out TE LSAs for TE links in TTZ in nodes outside of TTZ after some time (<1 hour) R6 R7 R8 R10 R9 R2 R3
T4 T2 T5 T8 T3 T9 T10 T1 T7 T6
TTZ 100
Normal link TTZ link
- 2. Originate TE LSAs for
virtualizing TTZ, and Not distribute TE LSAs for TTZ TE links to outside of TTZ
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After Migration to TTZ for ~1- hour
R6 R7 R8 R10 R9 R2 R3
T4 T2 T5 T8 T3 T9 T10 T1 T7 T6
TTZ 100
Normal link TTZ link On a node outside of TTZ: Topology with normal TE links (i.e., topology we see on up part) 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) R6 R7 R8 R10 R9 R2 R3
T4 T3 T10 T1
Normal link
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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 ~ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ TTZ-LSA-type: TTZ-TE-LSA-type (15?, TBD) for TTZ TE LSA LSAs for normal TE LSAs of TTZ can be flushed
- ut easily and quickly after migration to TTZ.
TLVs: Router Address TLV (from TE LSA) Link TLV (from TE LSA) TTZ ID TLV (TTZ Options TLV added into TE LSA for virtualinzing TTZ, explicit indication)
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Migration to TTZ
R6 R7 R8 R10 R9 R2 R3
T4 T2 T5 T8 T3 T9 T10 T1 T7 T6
TTZ 100
Normal link TTZ link R6 R7 R8 R10 R9 R2 R3
T4 T2 T5 T8 T3 T9 T10 T1 T7 T6
TTZ 100
Normal link TTZ link R6 R7 R8 R10 R9 R2 R3
T4 T2 T5 T8 T3 T9 T10 T1 T7 T6
TTZ 100
TTZ TE LSAs TE LSAs for virtualizing TTZ
- 1. TTZ TE links
distributed by TTZ TE LSA
- 2. Originate TE LSAs
for virtualizing TTZ Flushed out TE LSAs for links in TTZ soon
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After Migration to TTZ
R6 R7 R8 R10 R9 R2 R3
T4 T2 T5 T8 T3 T9 T10 T1 T7 T6
TTZ 100
Normal link TTZ link On a node outside of TTZ: Topology with normal TE links (i.e., topology we see on up part) 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) R6 R7 R8 R10 R9 R2 R3
T4 T3 T10 T1
Normal link
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Page 12 Start Initialization: candidate-list = {{root, MaxBW}}; result-tree = { }. Where for each edge node Ei, root = Ei; MaxBW is a maximum number. Select node with maximum bandwidth from candidate-list as working node k; remove it from candidate-list; add it into result-tree.
Is every other edge node Ej in result-tree?
Maximum bandwidth from Ei to 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;
- therwise (i.e., {x, BWx0} is in candidate-list), if BWx > BWx0,
then replace {x, BWx0} in candidate-list with {x, BWx}.
End
Yes
No
A1
Summarize TE for TTZ
SPF for finding maximum bandwidth path
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