draft-ietf-mpls-multicast-06.txt | draft-ietf-mpls-multicast-07.txt | |||
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Network Working Group D. Ooms, B. Sales | Network Working Group D. Ooms, B. Sales | |||
Internet Draft Alcatel | Internet Draft Alcatel | |||
Expiration Date: May 2002 W. Livens | Expiration Date: July 2002 W. Livens | |||
Colt Telecom | Colt Telecom | |||
A. Acharya | A. Acharya | |||
IBM | IBM | |||
F. Griffoul | F. Griffoul | |||
Ulticom | Ulticom | |||
F. Ansari | F. Ansari | |||
Bell Labs | Bell Labs | |||
November 2001 | January 2002 | |||
Framework for IP Multicast in MPLS | Framework for IP Multicast in MPLS | |||
draft-ietf-mpls-multicast-06.txt | draft-ietf-mpls-multicast-07.txt | |||
Status of this Memo | Status of this Memo | |||
This document is an Internet-Draft and is in full conformance with | This document is an Internet-Draft and is in full conformance with | |||
all provisions of Section 10 of RFC2026. | all provisions of Section 10 of RFC2026. | |||
Internet-Drafts are working documents of the Internet Engineering | Internet-Drafts are working documents of the Internet Engineering | |||
Task Force (IETF), its areas, and its working groups. Note that | Task Force (IETF), its areas, and its working groups. Note that | |||
other groups may also distribute working documents as Internet- | other groups may also distribute working documents as Internet- | |||
Drafts. | Drafts. | |||
skipping to change at page 3, line 34 | skipping to change at page 3, line 34 | |||
RSVP Resource reSerVation Protocol | RSVP Resource reSerVation Protocol | |||
SPT-bit Shortest Path Tree [DEER] | SPT-bit Shortest Path Tree [DEER] | |||
SSM Source Specific Multicast | SSM Source Specific Multicast | |||
TCP Transmission Control Protocol | TCP Transmission Control Protocol | |||
UDP User Datagram Protocol | UDP User Datagram Protocol | |||
VC Virtual Circuit | VC Virtual Circuit | |||
VCI Virtual Circuit Identifier | VCI Virtual Circuit Identifier | |||
VP Virtual Path | VP Virtual Path | |||
VPI Virtual Path Identifier | VPI Virtual Path Identifier | |||
Changes: | ||||
02->05 (problem in IETF db): incorporate WG last call comments | ||||
05->06: no changes | ||||
1. Introduction | 1. Introduction | |||
In an MPLS cloud the routes are determined by a L3 routing protocol. | In an MPLS cloud the routes are determined by a L3 routing protocol. | |||
These routes can then be mapped onto L2 paths to enhance network | These routes can then be mapped onto L2 paths to enhance network | |||
performance. Besides this, MPLS offers a vehicle for enhanced | performance. Besides this, MPLS offers a vehicle for enhanced | |||
network services such as QoS/CoS, traffic engineering, etc. | network services such as QoS/CoS, traffic engineering, etc. | |||
Current unicast routing protocols generate a same (optimal) shortest | Current unicast routing protocols generate a same (optimal) shortest | |||
path in steady state for a certain (source, destination)-pair. Remark | path in steady state for a certain (source, destination)-pair. Remark | |||
that unicast protocols can behave slightly different with regard to | that unicast protocols can behave slightly different with regard to | |||
skipping to change at page 11, line 42 | skipping to change at page 11, line 29 | |||
goes around a loop, copies of the packet may be emitted from the loop | goes around a loop, copies of the packet may be emitted from the loop | |||
if branches exist in the loop. | if branches exist in the loop. | |||
Currently loop detection is a configurable option in LDP and a | Currently loop detection is a configurable option in LDP and a | |||
decision on the mechanism for loop prevention is postponed. | decision on the mechanism for loop prevention is postponed. | |||
3.8. Mapping of characteristics on existing protocols | 3.8. Mapping of characteristics on existing protocols | |||
The above characteristics are summarized in Table 1 for a non- | The above characteristics are summarized in Table 1 for a non- | |||
exhaustive list of existing IP multicast routing protocols: DVMRP | exhaustive list of existing IP multicast routing protocols: DVMRP | |||
[PUSA], MOSPF [MOY], CBT [BALL], PIM-DM [DEER], PIM-SM [DEE2], SSM | [PUSA], MOSPF [MOY], CBT [BALL], PIM-DM [ADAM], PIM-SM [DEER], SSM | |||
[HOLB], SM [PERL]. | [HOLB], SM [PERL]. | |||
+------------------+------+------+------+------+------+------+------+ | +------------------+------+------+------+------+------+------+------+ | |||
| |DVMRP |MOSPF |CBT |PIM-DM|PIM-SM|SSM |SM | | | |DVMRP |MOSPF |CBT |PIM-DM|PIM-SM|SSM |SM | | |||
+------------------+------+------+------+------+------+------+------+ | +------------------+------+------+------+------+------+------+------+ | |||
|Aggregation |no |no |no |no |no |no |no | | |Aggregation |no |no |no |no |no |no |no | | |||
+------------------+------+------+------+------+------+------+------+ | +------------------+------+------+------+------+------+------+------+ | |||
|Flood & Prune |yes |no |no |yes |no |no |option| | |Flood & Prune |yes |no |no |yes |no |no |option| | |||
+------------------+------+------+------+------+------+------+------+ | +------------------+------+------+------+------+------+------+------+ | |||
|Tree Type |source|source|shared|source|both |source|shared| | |Tree Type |source|source|shared|source|both |source|shared| | |||
skipping to change at page 26, line 19 | skipping to change at page 25, line 47 | |||
Implicit label distribution is not applicable if the FEC-to-label | Implicit label distribution is not applicable if the FEC-to-label | |||
binding has been advertised prior to traffic arrival, e.g. explicit | binding has been advertised prior to traffic arrival, e.g. explicit | |||
routing (i.e. if all the information necessary to identify the FEC is | routing (i.e. if all the information necessary to identify the FEC is | |||
not present in the packet). | not present in the packet). | |||
Explicit distribution allows pre-establishment (before the arrival of | Explicit distribution allows pre-establishment (before the arrival of | |||
data) of LSPs with topology or request driven triggers. | data) of LSPs with topology or request driven triggers. | |||
11. Security Considerations | 11. Security Considerations | |||
This document raises no security issues. | In general, the use of multicast in an mpls environment poses no | |||
extra security issues beyond the ones that already exist in multicast | ||||
and mpls protocols as such. | ||||
The protocols described in this document are however not suited to | ||||
cross administrative boundaries. | ||||
When the multicast tree is determined by an existing multicast | ||||
routing protocol (this is the assumption made in this document, | ||||
except for the Explict Routing section), clearly no additional | ||||
security issues are introduced w.r.t. the shape of the tree (e.g. | ||||
unauthorized joining, tapping, blackholing, injecting traffic, ...). | ||||
These security issues should have been addressed in the | ||||
specifications of the multicast routing protocols. | ||||
In the MPLS context it is possible that control messages trigger L2 | ||||
resource allocations (e.g. LSPs). If security flaws would still be | ||||
present in the existing protocols (which possibly are not too harmful | ||||
in its original context) the abusive sending of such control messages | ||||
can yield more severe DoS attacks. | ||||
In case of an "explicit routed" tree that is calculated centrally, | ||||
sufficient authentication must be done on the control messages that | ||||
set up the tree in the network nodes. | ||||
12. Acknowledgements | 12. Acknowledgements | |||
The authors would like to thank Eric Rosen, Piet Van Mieghem, Philip | The authors would like to thank Eric Rosen, Piet Van Mieghem, Philip | |||
Dumortier, Hans De Neve, Jan Vanhoutte, Alex Mondrus and Gerard | Dumortier, Hans De Neve, Jan Vanhoutte, Alex Mondrus and Gerard | |||
Gastaud for the fruitful discussions and/or their thorough revision | Gastaud for the fruitful discussions and/or their thorough revision | |||
of this document. | of this document. | |||
References | Normative References | |||
Since this is an informational framework document (describing possible | ||||
solutions, without selecting a particular one), there are no normative | ||||
references. | ||||
Informative References | ||||
[ACHA] A. Acharya, R. Dighe and F. Ansari, "IP Switching Over Fast ATM | [ACHA] A. Acharya, R. Dighe and F. Ansari, "IP Switching Over Fast ATM | |||
Cell Transport (IPSOFACTO) : Switching Multicast flows", IEEE | Cell Transport (IPSOFACTO) : Switching Multicast flows", IEEE | |||
Globecom '97. | Globecom '97. | |||
[AWDU] D. Awduche, L. Berger, D. Gan, T. Li, G. Swallow and V. Sriniva- | [ADAM] A. Adams, J. Nicholas, W. Siadak, Protocol Independent Multicast | |||
san, "Extensions to RSVP for LSP Tunnels", Work In Progress | Version 2 Dense Mode Specification", Work In Progress. | |||
[ANDE] L. Andersson, P. Doolan, N. Feldman, A. Fredette and R. Thomas, | [ANDE] L. Andersson, P. Doolan, N. Feldman, A. Fredette and R. Thomas, | |||
"LDP specification", RFC3036, January 2001. | "LDP specification", RFC3036, January 2001. | |||
[AWDU] D. Awduche, L. Berger, D. Gan, T. Li, G. Swallow and V. Sriniva- | ||||
san, "RSVP-TE: Extensions to RSVP for LSP Tunnels", RFC3209, | ||||
December 2001 | ||||
[BALL] A. Ballardie, "Core Based Trees (CBT) Multicast Routing Archi- | [BALL] A. Ballardie, "Core Based Trees (CBT) Multicast Routing Archi- | |||
tecture", RFC2201, September 1997. | tecture", RFC2201, September 1997. | |||
[CONT] A. Conta, P. Doolan, A. Malis, "Use of Label Switching on Frame | [CONT] A. Conta, P. Doolan, A. Malis, "Use of Label Switching on Frame | |||
Relay Networks", RFC3034, January 2001. | Relay Networks", RFC3034, January 2001. | |||
[CRAW] E. Crawley, Editor, L. Berger, S. Berson, F. Baker, M. Borden | [CRAW] E. Crawley, Editor, L. Berger, S. Berson, F. Baker, M. Borden | |||
and J. Krawczyk, "A Framework for Integrated Services and RSVP | and J. Krawczyk, "A Framework for Integrated Services and RSVP | |||
over ATM", RFC2382, August 1998. | over ATM", RFC2382, August 1998. | |||
[DAVI] B. Davie, J. Lawrence, K. McCloghrie, Y. Rekhter, E. Rosen, G. | [DAVI] B. Davie, J. Lawrence, K. McCloghrie, Y. Rekhter, E. Rosen, G. | |||
Swallow and P. Doolan, "MPLS using LDP and ATM VC switching", | Swallow and P. Doolan, "MPLS using LDP and ATM VC switching", | |||
RFC3035, January 2001. | RFC3035, January 2001. | |||
[DEER] S. Deering, D. Estrin, D. Farinacci, A. Helmy, D. Thaler, S. | [DEER] S. Deering, D. Estrin, D. Farinacci, A. Helmy, D. Thaler, S. | |||
Deering, M. Handley, V. Jacobson, C. Liu, P. Sharma and L Wei, | Deering, M. Handley, V. Jacobson, C. Liu, P. Sharma and L Wei, | |||
"Protocol Independent Multicast-Sparse Mode (PIM-SM): Protocol | "Protocol Independent Multicast-Sparse Mode (PIM-SM): Protocol | |||
Specification", RFC 2117, June 1997. | Specification", RFC 2117, June 1997. | |||
[DEE2] S. Deering, D. Estrin, D. Farinacci, V. Jacobson, Protocol | [FARI] D. Farinacci, Y. Rekhter, E. Rosen and T. Qian, "Using PIM to | |||
Independent Multicast Version 2 Dense Mode Specification", Work | Distribute MPLS Labels for Multicast Routes", Work In Progress. | |||
In Progress. | ||||
[FARI] D. Farinacci, Y. Rekhter and E. Rosen, "Using PIM to Distribute | ||||
MPLS Labels for Multicast Routes", Work In Progress. | ||||
[FENN] W. Fenner, "Internet Group Management Protocol, IGMP, version | [FENN] W. Fenner, "Internet Group Management Protocol, IGMP, version | |||
2", RFC 2236, November 1997. | 2", RFC 2236, November 1997. | |||
[GARR] M. Garrett and M. Borden, "Interoperation of Controlled-Load | [GARR] M. Garrett and M. Borden, "Interoperation of Controlled-Load | |||
Service and Guaranteed Service with ATM", RFC2381, August 1998. | Service and Guaranteed Service with ATM", RFC2381, August 1998. | |||
[HOLB] H. Holbrook, B. Cain, "Source-Specific Multicast for IP", Work | [HOLB] H. Holbrook, B. Cain, "Source-Specific Multicast for IP", Work | |||
In Progress. | In Progress. | |||
End of changes. | ||||
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