Tomohiro Otani otani@kddilabs.jp Kenichi Ogaki ogaki@kddilabs.jp

1. GMPLS constraints consideration for CSPF path computationdraft-otani-ccamp-gmpls-cspf-constraints-00.txt Tomohiro Otani otani@kddilabs.jp Kenichi Ogaki ogaki@kddilabs.jp Arthi Ayyangar arthi@juniper.net 62st IETF Minneapolis, March. 2005

2. Summary of this BCP draft • This draft fits to the following charter item • “Definition of the mechanisms required to determine the route and properties of an established path (tunnel tracing)”. • This draft • states the problem of GMPLS CSPF path computation • Since these attributes are differently understood in an industrial environment (especially between optical and packet transport point of view), the path computation results sometimes vary. • tries to provide the guideline to consider GMPLS TE attributes for CSFP path computation at a source node. • TE attributes must be dealt with correctly in the case of CSPF path computation considering underlying physical and logical technologies of nodes as well as links. 62st IETF Minneapolis, March. 2005

3. Considered network model Ingress Transit Egress +-----+ Enc.:enc^in +-----+ Enc.:enc^tr +-----+ | |<---------//--------->| |<---------//--------->| | |SC: | Enc.: enc^tr |SC: | Enc.: enc^eg |SC: | |sc^in| BW:bw^in |sc^tr| BW:bw^tr |sc_eg| | |<---------//--------->| |<---------//--------->| | +-----+ BW: bw^tr +-----+ BW: bw^eg +-----+ • To correctly establish a GMPLS LSP from an ingress to an egress, a possible combination of GMPLS attributes is investigated. • Assumption for the simplicity • Switching capability (SC) must be consistent from an ingress node to an egress node [smaller switching granularity at ingress/egress nodes]. • Switching capability of transit nodes must be consistent with switching capability of a LSP to be created (not multi-layer). • Encoding-type must be consistent along a route to be established. 62st IETF Minneapolis, March. 2005

4. CSPF consideration (example) (2) Lambda switch capable (LSC) at transiting nodes +-----+---------+---------+---------+---------+-------------------+ |Case |LSP |Ingress |Transit |Egress |Remarks | +-----+---------+---------+---------+---------+-------------------+ | |SC |lambda |<=lambda |lambda |<=lambda |gmpls-routing-09 | |1|Enc|lambda |lambda |lambda |lambda |section 3.7, 3.10 | | |BW |X |<=bw^so |<=bw^tr |<=bw^en | | +-----+---------+---------+---------+---------+-------------------+ | |SC |lambda |<=lambda |lambda |<=lambda |gmpls-routing-09 | |2|Enc|SONET/SDH|SONET/SDH|SONET/SDH|SONET/SDH|section 3.6, 3.9 | | |BW |X |=bw^so |=bw^tr |=bw^en |Specified in G.691 | +-----+---------+---------+---------+---------+-------------------+ | |SC |lambda |<=lambda |lambda |<=lambda | | |3|Enc|Etherner |Ethernet |Ethernet |Ethernet | | | |BW |X |=bw^so |=bw^tr |=bw^en |Specified in IEEE | +-----+---------+---------+---------+---------+-------------------+ | |SC |lambda |<=lambda |lambda |<=lambda | | |4|Enc|OTN |OTN |OTN |OTN | | | |BW |X |=bw^so |=bw^tr |=bw^en |Specified in G.709 | +-----+---------+---------+---------+---------+-------------------+ The LSP to be created from an ingress GMPLS attributes to be satisfied in CSPF calculation (<=lambda means psc/L2SW/TDM/Lambda) 62st IETF Minneapolis, March. 2005

5. Next Steps • We would like cover all possible cases to create a concrete guideline of CSPF path computation in terms of GMPLS attributes • Encoding may have multiple matches, but discussion is needed. LSP encoding TE Link encoding • Ethernet Ethernet, Lamda, Fiber • SONET-SDH SONET-SDH, Lambda (true?), Fiber (true?) • Lambda Lambda, Fiber • Especially L2SC (discussion in this meeting) • Any feedback would be greatly appreciated. • Will investigate multi-layer consideration. 62st IETF Minneapolis, March. 2005