TSVWG WG James Polk Internet-Draft Subha Dhesikan Expires: September 4, 2009 Cisco Systems Intended Status: Standards Track (PS) March 4, 2009 Updates: RFC 2205, 2210, 4495 (if published as an RFC) Integrated Services (IntServ) Extension to Allow Multiple TSPECs draft-polk-tsvwg-intserv-multiple-tspec-00 Status of this Memo This Internet-Draft is submitted to IETF in full conformance with the provisions of BCP 78 and BCP 79. This document may contain material from IETF Documents or IETF Contributions published or made publicly available before November 10, 2008. The person(s) controlling the copyright in some of this material may not have granted the IETF Trust the right to allow modifications of such material outside the IETF Standards Process. 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The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html. This Internet-Draft will expire on September 4, 2009. Copyright Notice Copyright (c) 2009 IETF Trust and the persons identified as the document authors. All rights reserved. This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents in effect on the date of publication of this document (http://trustee.ietf.org/license-info). Please review these documents carefully, as they describe your Polk & Dhesikan Expires September 4, 2009 [Page 1] Internet-Draft RSVP Multi-TSPEC March 2009 rights and restrictions with respect to this document. Legal This documents and the information contained therein are provided on an "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY, THE IETF TRUST AND THE INTERNET ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION THEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. Abstract This document defines how Integrated Services (IntServ) includes multiple TSPECs in the same Resource Reservation Protocol (RSVPv1) reservation. This ability to send multiple TSPECs during reservation set up helps optimize an agreeable bandwidth through a network between endpoints in a single round trip. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Overview of the Multi_TSPEC Solution . . . . . . . . . . . . 6 3. Multiple Sender and Receiver in Single TSPEC Modification . . 8 3.1 New Multiple_Token_Bucket_Tspec Parameter in TSPEC . . . 8 3.2 SENDER_TSPEC and FLOWSPEC for Controlled-Load service . . 9 3.3 FLOWSPEC for Guaranteed service . . . . . . . . . . . . . 12 4. Multiple Sender and Receiver in Dual TSPEC Modification . . . 13 4.1 New Multiple_Token_Bucket_Tspec Parameter in TSPEC . . . 15 4.2 SENDER_TSPEC and FLOWSPEC for Controlled-Load service . . 16 4.3 FLOWSPEC for Guaranteed service . . . . . . . . . . . . . 20 5. Rules of Usage . . . . . . . . . . . . . . . . . . . . . . . 21 6. Security considerations . . . . . . . . . . . . . . . . . . . 21 7. IANA considerations . . . . . . . . . . . . . . . . . . . . . 21 8. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . 22 9. References . . . . . . . . . . . . . . . . . . . . . . . . . 22 9.1. Normative References . . . . . . . . . . . . . . . . . 22 9.2. Informative References . . . . . . . . . . . . . . . . 22 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . 23 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in RFC 2119 [RFC 2119]. Calling node = PATH generator throughout this document. Called node = RESV Generator throughout this document. Polk & Dhesikan Expires September 4, 2009 [Page 2] Internet-Draft RSVP Multi-TSPEC March 2009 1. Introduction This document defines how Integrated Services (IntServ) [RFC2210] includes multiple TSPECs in the same Resource Reservation Protocol (RSVPv1) [RFC2205] message. This ability to send multiple TSPECs during reservation set up helps optimize an agreeable bandwidth through a network between endpoints in a single round trip. There is a separation of function between the two specifications, in which RSVPv1 does not define the internal objects to establish controlled load or guarantee services. These are generally left to be opaque in RSVPv1. At the same time, IntServ does not require that RSVPv1 be the only reservation protocol for transporting both the controlled load or guaranteed service objects - but RSVP does often carry the objects anyway. This makes the two independent - yet related in usage, but are also frequently talked about as if they are one and the same. They are not. The TSPEC - for 'traffic specification' - contains the traffic characteristics of a sender's data flow and is a required object in a PATH message. The TSPEC is defined in RFC 2210 and is generally opaque to RSVP. The ADSPEC - for 'advertising specification' - is used to gather information along the downstream data path to aid the PATH receiver in the computation of QoS properties of this data path. The ADSPEC is also opaque to RSVP and is defined in RFC 2210. Both of these IntServ objects are part of the Sender Descriptor [RFC2205]. Once the Sender Descriptor is received at its destination node, after having traveled through the network of routers, the SENDER_TSPEC information is matched with the information gathered in the ADSPEC about the data path. Together, these two objects help the receiver build its FLOWSPEC for the RESV message. The RESV message establishes the reservation through the network of routers on the data path established by the PATH message. The TSPEC in the RESV message is called the RECEIVER_TSPEC. The SENDER_TSPEC is not changed in transit between endpoints (i.e., there are no bandwidth request adjustments along the way). However, the ADSPEC is changed, based on the conditions experienced through the network as the RSVP message travels hop-by-hop. Today, real-time applications have evolved such that they are able to dynamically adapt to available bandwidth, not just by dropping and adding layers, but also by reducing frame rates and resolution. Thus the current mechanism of the Integrated Services, and therefore RSVP, allowing the PATH generator to only provide one traffic specification and for the resulting RESV generator to only include one bandwidth request is limiting. With only one Sender_TSPEC in a PATH message and only one Receiver_TSPEC in a RESV message, applications will either have to Polk & Dhesikan Expires September 4, 2009 [Page 3] Internet-Draft RSVP Multi-TSPEC March 2009 accept the rejection or resort to multiple roundtrips to get the available bandwidth when its original request is not admitted. Since such real-time applications are time-sensitive, participating in multiple roundtrips for establishing bandwidth reservations is not a preferred option. The objective of this draft is to prevent such roundtrips as well as allow applications to successfully receive some level of bandwidth allotment that it can use for its sessions. While the ADSPEC provides an indication of the bandwidth available along the path and can be used by the RESV generator in creating the Receiver’s TSPEC, it does not prevent failures or multiple roundtrips as described above. The intermediary routers provide a best attempt estimate of available bandwidth in the ADSPEC object. However, it does not take into account external policy considerations (RFC 2215). In addition, the available bandwidth at the time of creating the ADSPEC may not be available at the time of an actual request in an RESV message. These reasons may cause the RESV message to be rejected. Therefore, the ADSPEC object cannot, by itself, satisfy the requirements of the current generations of real-time applications. It needs to be noted that the ADSPEC is unchanged by this new mechanism. If ADSPEC is included in the PATH message, it is recommended that the RESV generator use this object in determining the RECEIVER_TSPEC. This document creates a means for asking for more than one bandwidth within the same RSVP reservation set-up (both PATH and RESV) messages to optimize the determination of an agreed upon bandwidth for this reservation. Allowing multiple TSPECs within the same reservation message permits multiple bandwidths to be chosen from by the Called node, when the received ADSPEC is processed. This optimizes reservation establishment. This allows the applications to dynamically adapt their data stream to available network resources. The concept of RSVP signaling is shown in a single direction below, in Figure 1. Although the TSPEC is opaque to RSVP, it is shown along with the RSVP messages for completeness. The RSVP messages themselves need not be the focus of the reader. Instead, the number of round trips it takes to establish a reservation is the focus here. Polk & Dhesikan Expires September 4, 2009 [Page 4] Internet-Draft RSVP Multi-TSPEC March 2009 Calling node Rtr-1 Rtr-2 Rtr-N Called node | | | | | | PATH (with a TSPEC & ADSPEC) | |------------->|--------->|--------->|-------------->| | | | | | | RESV (with a TSPEC) | |<-------------|<---------|<---------|<--------------| | | | | | Figure 1. Concept of RSVP in a Single Direction Figure 1 shows a successful one-way reservation using RSVP and IntServ. Figure 2 shows a scenario where the RESV message, containing a RECEIVER_TSPEC, which is generated by the Called node, after considering both the Sender TSPEC and the ADSPEC, is rejected by an intermediary router. Calling node Rtr-1 Rtr-2 Rtr-N Called node | | | | | | PATH (with 1 TSPEC wanting 12Mbps) | |------------->|--------->|--------->|-------------->| | | | | | | | RESV (with 1 TSPEC wanting 12Mbps) | | | X <--------|<--------------| | | | | | | ResvErr (with Admission control Error=2) | | | |--------->|-------------->| | | | | | Figure 2. Concept of RSVP Rejection due to Limited Bandwidth The scenario above is where this 'multiple TSPEC' optimization helps. The Calling node may support multiple bandwidths for a given application (i.e., more than one codec for voice or video) and therefore might want to establish a reservation with the highest (or best) bandwidth that the network can provide for a particular codec. For example, bandwidths of: 12Mbps, 4Mbps, and 1.5Mbps for video for the three video codecs the Calling node supports. This document will discuss a general overview of this multi-TSPEC solution in section 2. The more detailed solutions are discussed in sections 3 and 4 are alternate solutions based on 2 of the 3 options discussed in section 2. WG discussions will result in one of the two sections being removed. This is why there is some duplicate Polk & Dhesikan Expires September 4, 2009 [Page 5] Internet-Draft RSVP Multi-TSPEC March 2009 (i.e., copied) text in the two sections. Section 5 will cover additional rules of usage of this IntServ extension, in addition to how this document needs to extend the scenario of when a router in the middle of a reservation cannot accept a preferred bandwidth (i.e., TSPEC), meaning previous routers that accepted that bandwidth, now have too much bandwidth reserved. This requires an extension to RFC 4495 (RSVP Bandwidth Reduction) to cover reservation establishment, as well as existing reservations. Obviously, in a reservation with only one codec - where one bandwidth is requested of the network, this mechanism is not necessary. 2. Overview of the Multi_TSPEC Solution Presently, this is the format of a PATH message [RFC2205]: ::= [ ] [ ... ] [ ] ::= ^^^^^^^^^^^^ [ ] The ADSPEC is optional in IntServ, therefore it may or may not be in the RSVP PATH message. Presently, the SENDER_TSPEC can have one bandwidth requested for this reservation. This is changed in this extension to IntServ. Given that the SENDER_TSPEC contains the bandwidth amount for this reservation request, we have a choice when wanting to include more than one bandwidth in the request: Option #1 - creating the ability to add one or more additional (and complete) SENDER_TSPECs, or Option #2 - create the ability for the one already allowed SENDER_TSPEC to carry more than one bandwidth amount for this same reservation. or Polk & Dhesikan Expires September 4, 2009 [Page 6] Internet-Draft RSVP Multi-TSPEC March 2009 Option #3 - create the ability for the existing SENDER_TSPEC to remain unchanged, but add an optional object to the such as this: ::= [ ] [ ] ^^^^^^^^^^^ Option #3 is an optimization to Option #1 in that Option #3 is an effectively a concatenation of Option #1 (i.e., instead of having separate additional objects, make them one longer object). Option #3 also have the advantage of being backwards compatible with existing implementations of [RFC2205] and [RFC2210], as optional objects do not need to be process, especially if they are not understood. Option #3 also applies to the RECEIVER_TSPEC(s) in the FLOWSPEC contained in the RESV message. NOTE: it is important to emphasize here that including more than one TSPEC in the RESV message does not cause more than one TSPEC to be granted. This Draft requires that the RESV generator arrange these multiple TSPECs in the order of preference. The benefit of this arrangement is that RSVP does not have to process the rest of the TSPECs if it can admit the first one. If a problem occurs with the PATH message - regardless of this extension, normal RSVP procedures apply (i.e., there is no new PathErr code created within this extension document) - resulting in a PathErr message being sent upstream towards the PATH originator, as usual. Since there are multiple TSPECs in a single RESV message, it is quite possible that a higher bandwidth is reserved at a previous downstream device. Thus, any device that grants a reservation that is not the highest will have to inform the previous downstream routers to reduce the bandwidth reserved for this particular session. The bandwidth reduction RFC [RFC4495] has the ability to partially preempt existing reservations. However, it does not address the need that this draft addresses. RFC 4495 defines an ability to preempt part of an existing reservation so as to admit a new incoming reservation with a higher priority, in lieu of tearing down the whole reservation with lower priority. It does not specify the capability to reduce the bandwidth a RESV set up along the data path before the reservation exists (from source to destination), when a subsequent router cannot support a more preferred TSPECs contained in that RESV. This document will extend the RFC 4495 defined error to work for previous hops while a reservation is being established. Polk & Dhesikan Expires September 4, 2009 [Page 7] Internet-Draft RSVP Multi-TSPEC March 2009 3. Multiple Sender and Receiver in Single TSPEC Modification Section 3 here discusses our solution from an Option #2 perspective (i.e., this section assumes there is a single group of TSPEC object, with multiple TSPECs within that object - for both SENDER_TSPECs (in a PATH) and RECEIVER_TSPECs (in a RESV)). See section 4 for the Option #3 discussion of our solution involving more than one TSPEC object (i.e., the original TSPEC as defined in [RFC2210] plus the new MULTI_TSPEC object defined here). These TSPEC parameters are used by data senders to describe the traffic parameters of traffic it expects to generate, and by QoS control services to describe the parameters of traffic for which the reservation should apply [RFC 2215]. This section specifies the detailed contents and wire format of a TSPEC that has been modified to allow multiple bandwidths, hence the term "Multiple TSPECs". 3.1 New Multiple_Token_Bucket_Tspec Parameter in TSPEC This extension to Integrated Services allows to use a new . This document creates the new Multiple_Token_Bucket_Tspec, with a parameter number of 125. This is IANA registered in this document. It is the combination of the two that indicates the type of object is proposed for this data flow, which is consistent with the rules established in [RF2210]. When there is more than one TSPEC, this MUST NOT be considered for more than one flow. These are OR choices for the same flow of data. In order to attain 3 reservations between two endpoints, 3 different reservation requests are required, not one reservation request with 3 TSPECs. This optimization, for example in a RESV FLOWSPEC, is to attain the available bandwidth in a single request, instead of a request-fail, (time wasted) another request-fail, (more time wasted) then finally a request-succeed. The above multiple roundtrips take longer than it needs to, and the purpose of this document is how to make this situation go away (for compliant nodes). Polk & Dhesikan Expires September 4, 2009 [Page 8] Internet-Draft RSVP Multi-TSPEC March 2009 3.2 SENDER_TSPEC and FLOWSPEC for Controlled-Load service Here is the object from [RFC2210]. It is used as a SENDER_TSPEC and as a RECEIVER_TSPEC (with one exception) requesting Controlled-Load service with different Service Headers: 31 24 23 16 15 8 7 0 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1 | 0 (a) | reserved | 7 (b) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2 | X (c) |0| reserved | 6 (d) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3 | 127 (e) | 0 (f) | 5 (g) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 4 | Token Bucket Rate [r] (32-bit IEEE floating point number) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 5 | Token Bucket Size [b] (32-bit IEEE floating point number) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 6 | Peak Data Rate [p] (32-bit IEEE floating point number) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 7 | Minimum Policed Unit [m] (32-bit integer) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 8 | Maximum Packet Size [M] (32-bit integer) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 3. TSPEC (in SENDER_TSPEC in PATH and RECEIVER_TSPEC in RESV) (a) - Message format version number (0) (b) - Overall length (7 words not including header) (c) - Service header, service number - '1' (Generic information) if in a PATH message; - '5' (Controlled-Load) if in a RESV message (d) - Length of service data, 6 words not including per-service header (e) - Parameter ID, parameter 127 (Token Bucket TSpec) (f) - Parameter 127 flags (none set) (g) - Parameter 127 length, 5 words not including per-service header Again, based on Option #2 - here is the new TSPEC object containing, for example, 3 (Multiple Token Bucket TSpec) TSPECs when requesting Controlled-Load service. This is based on option #2 mentioned above. The SENDER_TSPEC with a Multiple_Token_Bucket_Tspec will differ in only one respect when this is inserted into the FLOWSPEC of the RESV. That difference is in the service number field (c), in which the SENDER_TSPEC has a '1', the FLOWSPEC has a '5' - indicating Controlled Load service. Both will have the new Parameter ID of 125, which is IANA registered with this document. Polk & Dhesikan Expires September 4, 2009 [Page 9] Internet-Draft RSVP Multi-TSPEC March 2009 31 24 23 16 15 8 7 0 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1 | 0 (a) | reserved | 19 (b) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2 | 5 (c) |0| reserved | 18 (d) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3 | 125 (e) | 0 (f) | 5 (g) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 4 | Token Bucket Rate [r] (32-bit IEEE floating point number) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 5 | Token Bucket Size [b] (32-bit IEEE floating point number) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 6 | Peak Data Rate [p] (32-bit IEEE floating point number) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 7 | Minimum Policed Unit [m] (32-bit integer) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 8 | Maximum Packet Size [M] (32-bit integer) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 9 | 125 (e) | 0 (f) | 5 (g) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 10 | Token Bucket Rate [r] (32-bit IEEE floating point number) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 11 | Token Bucket Size [b] (32-bit IEEE floating point number) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 12 | Peak Data Rate [p] (32-bit IEEE floating point number) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 13 | Minimum Policed Unit [m] (32-bit integer) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 14 | Maximum Packet Size [M] (32-bit integer) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 15 | 125 (e) | 0 (f) | 5 (g) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 16 | Token Bucket Rate [r] (32-bit IEEE floating point number) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 17 | Token Bucket Size [b] (32-bit IEEE floating point number) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 18 | Peak Data Rate [p] (32-bit IEEE floating point number) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 19 | Minimum Policed Unit [m] (32-bit integer) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 20 | Maximum Packet Size [M] (32-bit integer) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 4. Multiple TSPECs for Controlled-Load service (a) - Message format version number (0) (b) - Overall length (19 words not including header) (c) - Service header, service number 5 (Controlled-Load) (d) - Length of controlled-load data, 18 words not including per-service header (e) - Parameter ID, parameter 125 (Multiple Token Bucket TSpec) (f) - Parameter 125 flags (none set) Polk & Dhesikan Expires September 4, 2009 [Page 10] Internet-Draft RSVP Multi-TSPEC March 2009 (g) - Parameter 125 length, 5 words not including per-service header The message format (a) remains the same for one TSPEC and multiple TSPECs. The Overall Length (b) increases to include the additional TSPECs only, plus the 2nd and 3rd Words - which also MUST NOT be repeated, which includes fields (c) and (d), and (e), (f) and (g), respectively. The Service header, here service number 5 (Controlled-Load) MUST remain the same. The services, Controlled-Load and Guaranteed MUST NOT be mixed within the same RESV message. In other words, if one TSPEC is a Controlled Load service TSPEC, the remaining TSPECs MUST be Controlled Load service. This same rule also is true for Guaranteed Service - if one TSPEC is for Guaranteed Service, the rest of the TSPECs in this PATH or RESV MUST be for Guaranteed Service. The Length of controlled-load data (d) also increases to account for the additional TSPECs. Each TSPEC is six 32-bit Words long (the per-service header plus the 5 values that are 1 Word each in length), therefore the length is in 6 Word increments for each additional TSPEC. Case in point, from the above Figure 4, Words 3-8 are the first TSPEC, Words 9-14 are the next TSPEC, and Words 15-20 are the final TSPEC in this example of 3 TSPECs in this FLOWSPEC. There is no limit placed on the number of TSPECs a particular FLOWSPEC can have. The TSPECS are included in the order of preference by the message generator (PATH and RESV) and MUST be maintained in that order. Within the Sender_Descriptor, any TSPEC that cannot be reserved - based on the information gathered in the ADSPEC, is not placed in the RESV. Otherwise, the order in which the TSPECs were in the PATH message MUST be in the same order they are in the FLOWSPEC in the RESV. This is the order of preference of the PATH generator, and MUST be maintained throughout the reservation establishment, unless the ADSPEC indicates one or more TSPECs cannot be granted, or one or more routers along the RESV path cannot grant a particular TSPEC. The ADSPEC directly affects which TSPEC(s) are placed in the RESV. At any router that a reservation cannot honor a TSPEC, this TSPEC MUST be removed from the RESV, or else another router along the RESV path might reserve that TSPEC. This rule ensures this cannot happen. Once one TSPEC has been removed from the RESV, the next in line TSPEC becomes the preferred TSPEC for that reservation. That router MUST generate a ResvErr message, containing an ERROR_SPEC object with a Policy Control Failure with Error code = 2 (Policy Control Polk & Dhesikan Expires September 4, 2009 [Page 11] Internet-Draft RSVP Multi-TSPEC March 2009 Failure), and an Error Value sub-code 102 (ERR_PARTIAL_PREEMPT) to the previous routers, clearing the now over allocation of bandwidth for this reservation. The difference between the previously accepted TSPEC bandwidth and the currently accepted TSPEC bandwidth is the amount this error identifies as the amount of bandwidth that is no longer required to be reserved. The ResvErr and the RESV messages are independent, and not normally sent by the same router. This aspect of this document is the extension to RFC 2205 (RSVPv1). If a RESV cannot grant the final TSPEC, normal RSVP rules apply with regard to the transmission of a particular ResvErr. 3.3 FLOWSPEC for Guaranteed service Here is the FLOWSPEC object from [RFC2215] when requesting Guaranteed service: 31 24 23 16 15 8 7 0 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1 | 0 (a) | Unused | 10 (b) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2 | 2 (c) |0| reserved | 9 (d) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3 | 127 (e) | 0 (f) | 5 (g) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 4 | Token Bucket Rate [r] (32-bit IEEE floating point number) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 5 | Token Bucket Size [b] (32-bit IEEE floating point number) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 6 | Peak Data Rate [p] (32-bit IEEE floating point number) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 7 | Minimum Policed Unit [m] (32-bit integer) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 8 | Maximum Packet Size [M] (32-bit integer) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 9 | 130 (h) | 0 (i) | 2 (j) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 10 | Rate [R] (32-bit IEEE floating point number) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 11 | Slack Term [S] (32-bit integer) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 5. Multiple TSPECs for Guaranteed service (a) - Message format version number (0) (b) - Overall length (9 words not including header) (c) - Service header, service number 2 (Guaranteed) (d) - Length of per-service data, 9 words not including per-service header (e) - Parameter ID, parameter 127 (Token Bucket TSpec) Polk & Dhesikan Expires September 4, 2009 [Page 12] Internet-Draft RSVP Multi-TSPEC March 2009 (f) - Parameter 127 flags (none set) (g) - Parameter 127 length, 5 words not including parameter header (h) - Parameter ID, parameter 130 (Guaranteed Service RSpec) (i) - Parameter 130 flags (none set) (j) - Parameter 130 length, 2 words not including parameter header The difference in structure between the Controlled-Load FLOWSPEC and Guaranteed FLOWSPEC is the RSPEC, defined in [RFC2212]. [Editor's Note: the authors are currently unsure if there needs to be a separate RSPEC for each TSPEC in the Guarantee service. Feedback is necessary before completing the Multi_TSPEC version of the above format. When the above is resolved, most of the same rules below Figure 4 will be copied here, with the special handling of the RSPEC added.] 4. Multiple Sender and Receiver in Dual TSPEC Modification It is unlikely that all routers along the path will have the necessary enhancements as per this extension at one given time. Therefore, it is necessary that such enhancements, such as this one, be made in a way that is backward compatible. For this extension to work, the minimal requirement is that both the Path and the Resv generator are enhanced with this extension as they will have to include the multiple TSPECs in the RSVP messages to invoke this feature. Other than that, the authors do not wish to impose any additional requirement on the RSVP-enabled routers along the path while warning that this feature’s benefit can only be realized if the routers along the path are enhanced with this extension. In order to provide for backward compatibility, the Sender's TSPEC and the RECEIVER_TSPEC are left untouched. This allows routers not having the extension to be able to process the Path and the Resv message. The additional TSPECs (MULTI_TSPEC] are included in the Path and in the Resv message as new, additional (optional) objects. Since these additional objects will have a class number of 11bbbbbb, it will allow older routers to ignore the object and forward it unexamined and unchanged, as defined in section 3.10 of [RFC 2205]. Section 4 here for the Option #3 discussion of our solution involving more than one TSPEC object (i.e., the original TSPEC as defined in [RFC2210] plus the new MULTI_TSPEC object defined here). Section 3 discusses our solution from an Option #2 perspective (i.e., this section assumes there is a single group of TSPEC object, with multiple TSPECs within that object - for both SENDER_TSPECs (in a PATH) and RECEIVER_TSPECs (in a RESV)). Polk & Dhesikan Expires September 4, 2009 [Page 13] Internet-Draft RSVP Multi-TSPEC March 2009 These TSPEC parameters are used by data senders to describe the traffic parameters of traffic it expects to generate, and by QoS control services to describe the parameters of traffic for which the reservation should apply [RFC 2215]. This section specifies the detailed contents and wire format of a TSPEC that has been modified to allow multiple bandwidths, hence the term "Multiple TSPECs". For the Sender_descriptor with in the PATH message, the original TSPEC remains where it is, and is untouched by this IntServ extension. What is new is the object, shown here: ::= [ ] [ ] ^^^^^^^^^^^ The preferred order of TSPECs sent by the PATH generator is this: - preferred TSPEC is in the original SENDER_TSPEC - the next in line preferred TSPEC is the first TSPEC in the MULTI_TSPEC object - the next in line preferred TSPEC is the second TSPEC in the MULTI_TSPEC object - etc... The flowspec composition depends upon the reservation style requested in the Resv message. Therefore, the following shows the inclusion of the MULTI_TSPEC object with each of the styles: WF Style: ::= ::= [MULTI-TSPEC] FF style: ::= [MULTI-TSPEC] | ::= [ ] [MULTI_TSPEC] Polk & Dhesikan Expires September 4, 2009 [Page 14] Internet-Draft RSVP Multi-TSPEC March 2009 SE style: ::= ::= [MULTI-TSPEC] ::= | This preferred order of TSPECs MUST be maintained within the SENDER_TSPEC, within the RESV Generator, and within the RECEIVER_TSPEC, with one exception: - if one or more preferred TSPECs cannot be granted by a router, or discovered during processing of the ADSPEC by the RESV Generator, each TSPEC that cannot be granted MUST be removed from this reservation establishment. The preferred order of the remaining TSPECs MUST be kept intact. If the recipient does not understand this extension, it ignores this MULTI_TSPEC object, and operates normally for a node receiving this RSVP message. [Editor's note: Subsections 4.1, 4.2 and 4.3 are written as if Option #3 were chosen by this document - therefore there is some repetitive text that will be removed from either section 3 (which focuses on Option #2) or section 4 (which focuses on Option #3). This will be done once the WG, if they take this on as a WG item, decides which Option is best moving forward.] 4.1 New Multiple_Token_Bucket_Tspec Parameter in TSPEC This extension to Integrated Services allows to use a new . This document creates the new Multiple_Token_Bucket_Tspec, with a parameter number of 125. This is IANA registered in this document. It is the combination of the two that indicates the type of object is proposed for this data flow, which is consistent with the rules established in [RF2210]. The original SENDER_TSPEC and RECEIVER_TSPEC maintain the of Token_Bucket_Tspec with a parameter number of 127. The new object, included in the Sender_Descriptor and FLOWSPEC has the parameter number of 125. When there is more than one TSPEC object, this MUST NOT be considered for more than one flow. These are OR choices for the same flow of data. In order to attain 3 reservations between two endpoints, 3 different reservation requests are required, not one Polk & Dhesikan Expires September 4, 2009 [Page 15] Internet-Draft RSVP Multi-TSPEC March 2009 reservation request with 3 TSPECs. This optimization, for example in a FLOWSPEC, is to attain the available bandwidth in a single request, instead of a request-fail, (time wasted) another request-fail, (more time wasted) then finally a request-succeed. The above multiple roundtrips take longer than it needs to, and the purpose of this document is how to make this situation go away (for compliant nodes). 4.2 SENDER_TSPEC and FLOWSPEC for Controlled-Load service Here is the object from [RFC2210]. It is used as a SENDER_TSPEC and as a RECEIVER_TSPEC (with one exception) requesting Controlled-Load service with different Service Headers: 31 24 23 16 15 8 7 0 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1 | 0 (a) | reserved | 7 (b) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2 | X (c) |0| reserved | 6 (d) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3 | 127 (e) | 0 (f) | 5 (g) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 4 | Token Bucket Rate [r] (32-bit IEEE floating point number) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 5 | Token Bucket Size [b] (32-bit IEEE floating point number) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 6 | Peak Data Rate [p] (32-bit IEEE floating point number) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 7 | Minimum Policed Unit [m] (32-bit integer) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 8 | Maximum Packet Size [M] (32-bit integer) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 6. TSPEC (in SENDER_TSPEC in PATH and RECEIVER_TSPEC in RESV) (a) - Message format version number (0) (b) - Overall length (7 words not including header) (c) - Service header, service number - '1' (Generic information) if in a PATH message; - '5' (Controlled-Load) if in a RESV message (d) - Length of service data, 6 words not including per-service header (e) - Parameter ID, parameter 127 (Token Bucket TSpec) Polk & Dhesikan Expires September 4, 2009 [Page 16] Internet-Draft RSVP Multi-TSPEC March 2009 (f) - Parameter 127 flags (none set) (g) - Parameter 127 length, 5 words not including per-service header For Option #3, Figure 3 is included in its original form for backwards compatibility reasons, as if there were only 1 TSPEC in the PATH or RESV. What is new when there are more than one TSPEC in this reservation message is the new MULTI_TSPEC object in Figure 7 containing, for example, 3 (Multiple_Token_Bucket_Tspec) TSPECs when requesting Controlled-Load service. The SENDER_TSPEC with a Multiple_Token_Bucket_Tspec will differ in only one respect when this is inserted into the FLOWSPEC of the RESV. That difference is in the service number field (c), in which the SENDER_TSPEC has a '1', the FLOWSPEC has a '5' - indicating Controlled Load service. Both will have the new Parameter ID of 125, which is IANA registered with this document. 31 24 23 16 15 8 7 0 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1 | 0 (a) | reserved | 19 (b) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2 | 5 (c) |0| reserved | 18 (d) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3 | 125 (e) | 0 (f) | 5 (g) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 4 | Token Bucket Rate [r] (32-bit IEEE floating point number) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 5 | Token Bucket Size [b] (32-bit IEEE floating point number) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 6 | Peak Data Rate [p] (32-bit IEEE floating point number) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 7 | Minimum Policed Unit [m] (32-bit integer) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 8 | Maximum Packet Size [M] (32-bit integer) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 9 | 125 (e) | 0 (f) | 5 (g) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 10 | Token Bucket Rate [r] (32-bit IEEE floating point number) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 11 | Token Bucket Size [b] (32-bit IEEE floating point number) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 12 | Peak Data Rate [p] (32-bit IEEE floating point number) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 13 | Minimum Policed Unit [m] (32-bit integer) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 14 | Maximum Packet Size [M] (32-bit integer) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 15 | 125 (e) | 0 (f) | 5 (g) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 16 | Token Bucket Rate [r] (32-bit IEEE floating point number) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Polk & Dhesikan Expires September 4, 2009 [Page 17] Internet-Draft RSVP Multi-TSPEC March 2009 17 | Token Bucket Size [b] (32-bit IEEE floating point number) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 18 | Peak Data Rate [p] (32-bit IEEE floating point number) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 19 | Minimum Policed Unit [m] (32-bit integer) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 20 | Maximum Packet Size [M] (32-bit integer) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 7. Multiple TSPECs for Controlled-Load service (a) - Message format version number (0) (b) - Overall length (19 words not including header) (c) - Service header, service number 5 (Controlled-Load) (d) - Length of controlled-load data, 18 words not including per-service header (e) - Parameter ID, parameter 125 (Multiple Token Bucket TSpec) (f) - Parameter 125 flags (none set) (g) - Parameter 125 length, 5 words not including per-service header This is for the 2nd through Nth preferred TSPEC in the PATH or RESV. The message format (a) remains the same for a second TSPEC and for more TSPECs. The Overall Length (b) increases to include the additional TSPECs only, plus the 2nd and 3rd Words - which also MUST NOT be repeated, which includes fields (c) and (d), and (e), (f) and (g), respectively. The Service header, here service number 5 (Controlled-Load) MUST remain the same. The services, Controlled-Load and Guaranteed MUST NOT be mixed within the same RESV message. In other words, if one TSPEC is a Controlled Load service TSPEC, the remaining TSPECs MUST be Controlled Load service. This same rule also is true for Guaranteed Service - if one TSPEC is for Guaranteed Service, the rest of the TSPECs in this PATH or RESV MUST be for Guaranteed Service. The Length of controlled-load data (d) also increases to account for the additional TSPECs. Each TSPEC is six 32-bit Words long (the per-service header plus the 5 values that are 1 Word each in length), therefore the length is in 6 Word increments for each additional TSPEC. Case in point, from the above Figure 4, Words 3-8 are the first TSPEC (2nd preferred), Words 9-14 are the next TSPEC (3rd preferred), and Words 15-20 are the final TSPEC (and 4th preferred) in this example of 3 TSPECs in this FLOWSPEC. There is no limit placed on the number of TSPECs a particular FLOWSPEC can have. Polk & Dhesikan Expires September 4, 2009 [Page 18] Internet-Draft RSVP Multi-TSPEC March 2009 The TSPECS are included in the order of preference by the message generator (PATH and RESV) and MUST be maintained in that order. Within the Sender_Descriptor, any TSPEC that cannot be reserved - based on the information gathered in the ADSPEC, is not placed in the RESV. Otherwise, the order in which the TSPECs were in the PATH message MUST be in the same order they are in the FLOWSPEC in the RESV. This is the order of preference of the PATH generator, and MUST be maintained throughout the reservation establishment, unless the ADSPEC indicates one or more TSPECs cannot be granted, or one or more routers along the RESV path cannot grant a particular TSPEC. The ADSPEC directly affects which TSPEC(s) are placed in the RESV. At any router that a reservation cannot honor a TSPEC, this TSPEC MUST be removed from the RESV, or else another router along the RESV path might reserve that TSPEC. This rule ensures this cannot happen. Once one TSPEC has been removed from the RESV, the next in line TSPEC becomes the preferred TSPEC for that reservation. That router MUST generate a ResvErr message, containing an ERROR_SPEC object with a Policy Control Failure with Error code = 2 (Policy Control Failure), and an Error Value sub-code 102 (ERR_PARTIAL_PREEMPT) to the previous routers, clearing the now over allocation of bandwidth for this reservation. The difference between the previously accepted TSPEC bandwidth and the currently accepted TSPEC bandwidth is the amount this error identifies as the amount of bandwidth that is no longer required to be reserved. The ResvErr and the RESV messages are independent, and not normally sent by the same router. This aspect of this document is the extension to RFC 2205 (RSVPv1). If a RESV cannot grant the final TSPEC, normal RSVP rules apply with regard to the transmission of a particular ResvErr. Polk & Dhesikan Expires September 4, 2009 [Page 19] Internet-Draft RSVP Multi-TSPEC March 2009 4.3 FLOWSPEC for Guaranteed service Here is the FLOWSPEC object from [RFC2215] when requesting Guaranteed service: 31 24 23 16 15 8 7 0 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 1 | 0 (a) | Unused | 10 (b) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 2 | 2 (c) |0| reserved | 9 (d) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 3 | 127 (e) | 0 (f) | 5 (g) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 4 | Token Bucket Rate [r] (32-bit IEEE floating point number) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 5 | Token Bucket Size [b] (32-bit IEEE floating point number) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 6 | Peak Data Rate [p] (32-bit IEEE floating point number) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 7 | Minimum Policed Unit [m] (32-bit integer) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 8 | Maximum Packet Size [M] (32-bit integer) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 9 | 130 (h) | 0 (i) | 2 (j) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 10 | Rate [R] (32-bit IEEE floating point number) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 11 | Slack Term [S] (32-bit integer) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 5. Multiple TSPECs for Guaranteed service (a) - Message format version number (0) (b) - Overall length (9 words not including header) (c) - Service header, service number 2 (Guaranteed) (d) - Length of per-service data, 9 words not including per-service header (e) - Parameter ID, parameter 127 (Token Bucket TSpec) (f) - Parameter 127 flags (none set) (g) - Parameter 127 length, 5 words not including parameter header (h) - Parameter ID, parameter 130 (Guaranteed Service RSpec) (i) - Parameter 130 flags (none set) (j) - Parameter 130 length, 2 words not including parameter header The difference in structure between the Controlled-Load FLOWSPEC and Guaranteed FLOWSPEC is the RSPEC, defined in [RFC2212]. [Editor's Note: the authors are currently unsure if there needs to be a separate RSPEC for each TSPEC in the Guarantee service. Feedback is necessary before completing the Multi_TSPEC version of the above format. Polk & Dhesikan Expires September 4, 2009 [Page 20] Internet-Draft RSVP Multi-TSPEC March 2009 When the above is resolved, most of the same rules below Figure 4 will be copied here, with the special handling of the RSPEC added.] 5. Rules of Usage [Editor's Note: Most of the rules of usage right now are in the Controlled Load section of this document (section 3.2). Once the issue wrt the RSPEC in the Guaranteed Service FLOWSPEC is solved, most (if not all) the globally applicable rules of usage will move into this section 4.] - RFC 4495 articulates why a ResvErr is more appropriate to use for reducing the bandwidth of an existing reservation, vs. a ResvTear. - Refreshes only include the TSPECs that were accepted. One SHOULD be sent immediately upon the Calling node receiving the RESV, to ensure all routers in this flow are synchronized with which TSPEC is in place. - Periodically it MAY be appropriate to attempt to increase the bandwidth of an accepted reservation with one of the TSPECs that were not accepted by the network when the reservation was first installed. This SHOULD NOT occur too regularly. This document currently offers no guidance on the frequency of this bump request for a rejected TSPEC from the PATH. - ...there is more coming here... 6. Security considerations The security considerations for this document do not exceed what is already in RFC 2205 (RESV) or RFC 2210 (IntServ), as nothing in either of those documents prevent a node from requesting a lot of bandwidth in a single TSPEC. This document merely reduces the signaling traffic load on the network by allowing many requests that fall under the same policy controls to be included in a single round-trip message exchange. Further, this document does not increase the security risk(s) to that defined in RFC 4495, where this document creates additional meaning to the RFC 4495 created error code 102. 7. IANA considerations This document IANA registers the following new parameter name in the Integ-serv assignments at [IANA]: Polk & Dhesikan Expires September 4, 2009 [Page 21] Internet-Draft RSVP Multi-TSPEC March 2009 Registry Name: Parameter Names Registry: Value Description Reference -------- -------------------------------------------- --------- 125 Multiple_Token_Bucket_Tspec [RFCXXXX] Where RFCXXXX is replaced with the RFC number assigned to this Document. 8. Acknowledgments Your name here... 9. References 9.1. Normative References [RFC2119] S. Bradner, "Key words for use in RFCs to Indicate Requirement Levels", RFC 2119, March 1997 [RFC2205] R. Braden, Ed., L. Zhang, S. Berson, S. Herzog, S. Jamin, "Resource ReSerVation Protocol (RSVP) -- Version 1 Functional Specification", RFC 2205, September 1997 [RFC2210] J. Wroclawski, "The Use of RSVP with IETF Integrated Services", RFC 2210, September 1997 [RFC2212] S. Shenker, C. Partridge, R. Guerin, "Specification of Guaranteed Quality of Service", RFC 2212, September 1997 [RFC2215] S. Shenker, J. Wroclawski, "General Characterization Parameters for Integrated Service Network Elements", RFC 2212, September 1997 [RFC4495] J. Polk, S. Dhesikan, "A Resource Reservation Protocol (RSVP) Extension for the Reduction of Bandwidth of a Reservation Flow", RFC 4495, May 2006 9.2. Informative References [IANA] http://www.iana.org/assignments/integ-serv Polk & Dhesikan Expires September 4, 2009 [Page 22] Internet-Draft RSVP Multi-TSPEC March 2009 Authors' Addresses James Polk 3913 Treemont Circle Colleyville, Texas, USA +1.817.271.3552 mailto: jmpolk@cisco.com Subha Dhesikan Cisco Systems 170 W. Tasman Drive San Jose, CA 95134 USA mailto: sdhesika@cisco.com Polk & Dhesikan Expires September 4, 2009 [Page 23]