| Network Working Group | G. Mirsky |
| Internet-Draft | X. Min |
| Intended status: Standards Track | ZTE Corp. |
| Expires: January 7, 2020 | G. Jun |
| ZTE Corporation | |
| H. Nydell | |
| Accedian Networks | |
| R. Foote | |
| Nokia | |
| July 6, 2019 |
Simple Two-way Active Measurement Protocol Optional Extensions
draft-mirsky-ippm-stamp-option-tlv-05
This document describes optional extensions to Simple Two-way Active Measurement Protocol (STAMP) which enable measurement performance metrics in addition to ones supported by the STAMP base specification.
This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet-Drafts is at https://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress."
This Internet-Draft will expire on January 7, 2020.
Copyright (c) 2019 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 (https://trustee.ietf.org/license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License.
Simple Two-way Active Measurement Protocol (STAMP) [I-D.ietf-ippm-stamp] supports the use of optional extensions that use Type-Length-Value (TLV) encoding. Such extensions are to enhance the STAMP base functions, such as measurement of one-way and round-trip delay, latency, packet loss, as well as ability to detect packet duplication and out-of-order delivery of the test packets. This specification provides definitions of optional STAMP extensions, their formats, and theory of operation.
STAMP - Simple Two-way Active Measurement Protocol
DSCP - Differentiated Services Code Point
ECN - Explicit Congestion Notification
NTP - Network Time Protocol
PTP - Precision Time Protocol
HMAC Hashed Message Authentication Code
TLV Type-Length-Value
BITS Building Integrated Timing Supply
SSU Synchronization Supply Unit
GPS Global Positioning System
GLONASS Global Orbiting Navigation Satellite System
LORAN-C Long Range Navigation System Version C
MBZ Must Be Zeroed
CoS Class of Service
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all capitals, as shown here.
STAMP Session-Sender transmits test packets to STAMP Session-Reflector. STAMP Session-Reflector receives Session-Sender's packet and acts according to the configuration and optional control information communicated in the Session-Sender's test packet. STAMP defines two different test packet formats, one for packets transmitted by the STAMP-Session-Sender and one for packets transmitted by the STAMP-Session-Reflector. STAMP supports two modes: unauthenticated and authenticated. Unauthenticated STAMP test packets are compatible on the wire with unauthenticated TWAMP-Test [RFC5357] packet formats.
By default, STAMP uses symmetrical packets, i.e., the size of the packet transmitted by Session-Reflector equals the size of the packet received by the Session-Reflector.
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Sequence Number |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Timestamp |
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Error Estimate | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
| |
| |
| MBZ (30 octets) |
| |
| |
| |
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
~ Value ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 1: STAMP Session-Sender test packet format with TLV in unauthenticated mode
Figure 1 displays the format of STAMP Session-Sender test packet in unauthenticated mode that includes a TLV.
The MBZ (Must Be Zeroed) field of a test packet transmitted by a STAMP Session-Sender MUST be 30 octets long. A STAMP Session-Sender test packet MUST NOT use the Reflect Octets capability defined in [RFC6038].
TLVs (Type-Length-Value tuples) have the two octets long Type field, two octets long Length field that is the length of the Value field in octets. Type values, see Section 5.1, less than 32768 identify mandatory TLVs that MUST be supported by an implementation. Type values greater than or equal to 32768 identify optional TLVs that SHOULD be ignored if the implementation does not understand or support them. If a Type value for TLV or sub-TLV is in the range for Vendor Private Use, the Length MUST be at least 4, and the first four octets MUST be that vendor's the Structure of Management Information (SMI) Private Enterprise Number, in network octet order. The rest of the Value field is private to the vendor. Following sections describe the use of TLVs for STAMP that extend STAMP capability beyond its base specification.
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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Sequence Number | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Timestamp | | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Error Estimate | MBZ | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Receive Timestamp | | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Session-Sender Sequence Number | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Session-Sender Timestamp | | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Session-Sender Error Estimate | MBZ | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |Ses-Sender TTL | MBZ2 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Type | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ ~ Value ~ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 2: STAMP Session-Reflector test packet format with TLV in unauthenticated mode
Figure 2 displays the format of STAMP Session-Reflector test packet in unauthenticated mode that includes a TLV.
A STAMP node, whether Session-Sender or Session-Reflector, receiving a test packet MUST determine whether the packet is a base STAMP packet or includes one or more TLVs. The node MUST compare the value in the Length field of the UDP header and the length of the base STAMP test packet in the mode, unauthenticated or authenticated based on the configuration of the particular STAMP test session. If the difference between the two values is larger than the length of UDP header, then the test packet includes one or more STAMP TLVs that immediately follow the base STAMP test packet.
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Extra Padding Type | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
~ Extra Padding ~
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 3: Extra Padding TLV
The Extra Padding TLV is similar to the Packet Padding field in TWAMP-Test packet [RFC5357]. The in STAMP the Packet Padding field is used to ensure symmetrical size between Session-Sender and Session-Reflector test packets. Extra Padding TLV MUST be used to create STAMP test packets of larger size.
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Location Type | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Source MAC |
+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| | Reserved A |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
~ Destination IP Address ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
~ Source IP Address ~
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Dest.port | Src.Port | Reserved B |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 4: Session-Reflector Location TLV
STAMP session-sender MAY include the Location TLV to request information from the session-reflector. The session-sender SHOULD NOT fill any information fields except for Type and Length. The session-reflector MUST validate the Length value against the address family of the transport encapsulating the STAMP test packet. If the value of the Length field is invalid, the session-reflector MUST zero all fields and MUST NOT return any information to the session-sender. The session-reflector MUST ignore all other fields of the received Location TLV.
The Location TLV MAY be used to determine the last-hop addressing for STAMP packets including source and destination IP addresses as well as the MAC address of the last-hop router. Last-hop MAC address MAY be monitored by the Session-Sender whether there has been a path switch on the last hop, closest to the Session-Reflector. The IP addresses and UDP port will indicate if there is a NAT router on the path, and allows the Session-Sender to identify the IP address of the Session-Reflector behind the NAT, detect changes in the NAT mapping that could cause sending the STAMP packets to the wrong Session-Reflector.
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Timestamp Information Type | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Sync. Src In | Timestamp In | Sync. Src Out | Timestamp Out |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 5: Timestamp Information TLV
STAMP session-sender MAY include the Timestamp Information TLV to request information from the session-reflector. The session-sender SHOULD NOT fill any information fields except for Type and Length. The session-reflector MUST validate the Length value of the STAMP test packet. If the value of the Length field is invalid, the session-reflector MUST zero all fields and MUST NOT return any information to the session-sender.
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Class of Service Type | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| DSCP1 | DSCP2 |ECN| Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 6: Class of Service TLV
The STAMP session-sender MAY include Class of Service (CoS) TLV in the STAMP test packet. If the CoS TLV is present in the STAMP test packet and the value of the DSCP1 field is zero, then the STAMP session-reflector MUST copy the values of Differentiated Services Code Point (DSCP) ECN fields from the received STAMP test packet into DSCP2 and ECN fields respectively of the CoS TLV of the reflected STAMP test packet. If the value of the DSCP1 field is non-zero, then the STAMP session-reflector MUST use DSCP1 value from the CoS TLV in the received STAMP test packet as DSCP value of STAMP reflected test packet and MUST copy DSCP and ECN values of the received STAMP test packet into DSCP2 and ECN fields of Class of Service TLV in the STAMP reflected a packet. The Session-Sender, upon receiving the reflected packet, will save the DSCP and ECN values for analysis of the CoS in the reverse direction.
A STAMP Session-Sender that includes the CoS TLV sets the value of the DSCP1 field and zeroes the value of the DSCP2 field. A STAMP Session-Reflector that received the test packet with the CoS TLV MUST include the CoS TLV in the reflected test packet. Also, the Session-Reflector MUST copy the value of the DSCP field of the IP header of the received STAMP test packet into the DSCP2 field in the reflected test packet. And, at last, the Session-Reflector MUST set the value of the DSCP field in the IP header of the reflected test packet equal to the value of the DSCP1 field of the test packet it has received.
Re-mapping of CoS in some use cases, for example, in mobile backhaul networks is used to provide multiple services, i.e., 2G, 3G, LTE, over the same network. But if it is misconfigured, then it is often difficult to diagnose the root cause of the problem that is viewed as an excessive packet drop of higher level service while packet drop for lower service packets is at a normal level. Using CoS TLV in STAMP test helps to troubleshoot the existing problem and also verify whether DiffServ policies are processing CoS as required by the configuration.
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Direct Measurement Type | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Session-Sender Tx counter (S_TxC) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Session-Reflector Rx counter (R_RxC) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Session-Reflector Tx counter (R_TxC) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 7: Direct Measurement TLV
The Direct Measurement TLV enables collection of "in profile" IP packets that had been transmitted and received by the Session-Sender and Session-Reflector respectfully. The definition of "in-profile packet" is outside the scope of this document.
IANA is requested to create the STAMP TLV Type registry. All code points in the range 1 through 32759 in this registry shall be allocated according to the "IETF Review" procedure as specified in [RFC8126]. Code points in the range 32760 through 65279 in this registry shall be allocated according to the "First Come First Served" procedure as specified in [RFC8126]. Remaining code points are allocated according to Table 1:
| Value | Description | Reference |
|---|---|---|
| 0 | Reserved | This document |
| 1- 32767 | Mandatory TLV, unassigned | IETF Review |
| 32768 - 65279 | Optional TLV, unassigned | First Come First Served |
| 65280 - 65519 | Experimental | This document |
| 65520 - 65534 | Private Use | This document |
| 65535 | Reserved | This document |
This document defines the following new values in STAMP TLV Type registry:
| Value | Description | Reference |
|---|---|---|
| TBA1 | Extra Padding | This document |
| TBA2 | Location | This document |
| TBA3 | Timestamp Information | This document |
| TBA4 | Class of Service | This document |
| TBA5 | Direct Measurement | This document |
IANA is requested to create Synchronization Source sub-registry as part of STAMP TLV Type registry. All code points in the range 1 through 127 in this registry shall be allocated according to the "IETF Review" procedure as specified in [RFC8126]. Code points in the range 128 through 239 in this registry shall be allocated according to the "First Come First Served" procedure as specified in [RFC8126]. Remaining code points are allocated according to Table 1:
| Value | Description | Reference |
|---|---|---|
| 0 | Reserved | This document |
| 1- 127 | Unassigned | IETF Review |
| 128 - 239 | Unassigned | First Come First Served |
| 240 - 249 | Experimental | This document |
| 250 - 254 | Private Use | This document |
| 255 | Reserved | This document |
This document defines the following new values in Synchronization Source sub-registry:
| Value | Description | Reference |
|---|---|---|
| 1 | NTP | This document |
| 2 | PTP | This document |
| 3 | SSU/BITS | This document |
| 4 | GPS/GLONASS/LORAN-C | This document |
| 5 | Local free-running | This document |
IANA is requested to create Timestamping Method sub-registry as part of STAMP TLV Type registry. All code points in the range 1 through 127 in this registry shall be allocated according to the "IETF Review" procedure as specified in [RFC8126]. Code points in the range 128 through 239 in this registry shall be allocated according to the "First Come First Served" procedure as specified in [RFC8126]. Remaining code points are allocated according to Table 1:
| Value | Description | Reference |
|---|---|---|
| 0 | Reserved | This document |
| 1- 127 | Unassigned | IETF Review |
| 128 - 239 | Unassigned | First Come First Served |
| 240 - 249 | Experimental | This document |
| 250 - 254 | Private Use | This document |
| 255 | Reserved | This document |
This document defines the following new values in Timestamping Methods sub-registry:
| Value | Description | Reference |
|---|---|---|
| 1 | HW assist | This document |
| 2 | SW local | This document |
| 3 | Control plane | This document |
Use of HMAC in authenticated mode may be used to simultaneously verify both the data integrity and the authentication of the STAMP test packets.
Authors much appreciate the thorough review and thoughful comments received from Tianran Zhou.
| [I-D.ietf-ippm-stamp] | Mirsky, G., Jun, G., Nydell, H. and R. Foote, "Simple Two-way Active Measurement Protocol", Internet-Draft draft-ietf-ippm-stamp-06, April 2019. |
| [RFC2119] | Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997. |
| [RFC5357] | Hedayat, K., Krzanowski, R., Morton, A., Yum, K. and J. Babiarz, "A Two-Way Active Measurement Protocol (TWAMP)", RFC 5357, DOI 10.17487/RFC5357, October 2008. |
| [RFC6038] | Morton, A. and L. Ciavattone, "Two-Way Active Measurement Protocol (TWAMP) Reflect Octets and Symmetrical Size Features", RFC 6038, DOI 10.17487/RFC6038, October 2010. |
| [RFC8126] | Cotton, M., Leiba, B. and T. Narten, "Guidelines for Writing an IANA Considerations Section in RFCs", BCP 26, RFC 8126, DOI 10.17487/RFC8126, June 2017. |
| [RFC8174] | Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, May 2017. |
| [IEEE.1588.2008] | "Standard for a Precision Clock Synchronization Protocol for Networked Measurement and Control Systems", IEEE Standard 1588, March 2008. |
| [RFC5905] | Mills, D., Martin, J., Burbank, J. and W. Kasch, "Network Time Protocol Version 4: Protocol and Algorithms Specification", RFC 5905, DOI 10.17487/RFC5905, June 2010. |