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INTAREA/Network Working Group                                   J. Zhu
Internet Draft                                                  Intel
Intended status: Informational                            S. Kanugovi
Expires: November 14,2020                                       Nokia
                                                          May 14, 2020

            Generic Multi-Access (GMA) Encapsulation Protocol
                         draft-zhu-intarea-gma-07


Abstract

   Today, a device can be simultaneously connected to multiple
   networks, e.g. Wi-Fi, LTE, 5G, and DSL. It is desirable to combine
   them seamlessly to improve quality of experience. Such
   optimization requires additional control information, e.g.
   Sequence Number, in each (IP) data packet. This document presents
   a new light-weight and flexible encapsulation protocol for this
   need. The solution has been developed by the authors based on
   their experiences in multiple standards bodies including the IETF
   and 3GPP, is not an Internet Standard and does not represent the
   consensus opinion of the IETF. This document will enable other
   developers to build interoperable implementations.

Status of this Memo

   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), its areas, and its working groups.  Note that
   other groups may also distribute working documents as Internet-
   Drafts.

   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."

   The list of current Internet-Drafts can be accessed at
   http://www.ietf.org/ietf/1id-abstracts.txt

   The list of Internet-Draft Shadow Directories can be accessed at
   http://www.ietf.org/shadow.html

   This Internet-Draft will expire on November 14, 2020.




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Copyright Notice

   Copyright (c) 2020 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
   (http://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.



Table of Contents

   1. Introduction ................................................. 2
   2. Conventions used in this document ............................ 4
   3. Use Case ..................................................... 4
   4. GMA Encapsulation Formats .................................... 5
   5. Fragmentation ................................................ 9
   6. Concatenation ............................................... 11
   7. Security Considerations ..................................... 12
   8. IANA Considerations ......................................... 12
   9. References .................................................. 12
      9.1. Normative References ..................................12
      9.2. Informative References ................................12

1. Introduction

   Figure 1 shows the Multi-Access Management Service (MAMS) user-
   plane protocol stack [MAMS], which has been used in today's multi-
   access solutions [ATSSS] [LWIPEP] [GRE]. It consists of two
   layers: convergence and adaptation.

   The convergence layer is responsible for multi-access operations,
   including multi-link (path) aggregation, splitting/reordering,
   lossless switching/retransmission, fragmentation, concatenation,
   etc. It operates on top of the adaptation layer in the protocol
   stack. From the Transmitter perspective, a User Payload (e.g. IP
   packet) is processed by the convergence layer first, and then by
   the adaptation layer before being transported over a delivery
   connection; from the Receiver perspective, an IP packet received
   over a delivery connection is processed by the adaptation layer
   first, and then by the convergence layer.

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          +-----------------------------------------------------+
          |   User Payload, e.g., IP Protocol Data Unit (PDU)   |
          +-----------------------------------------------------+
       +-----------------------------------------------------------+
       |  +-----------------------------------------------------+  |
       |  | Multi-Access (MX) Convergence Layer                 |  |
       |  +-----------------------------------------------------+  |
       |  +-----------------------------------------------------+  |
       |  | MX Adaptation   | MX Adaptation   | MX Adaptation   |  |
       |  | Layer           | Layer           | Layer           |  |
       |  | (optional)      | (optional)      | (optional)      |  |
       |  +-----------------+-----------------+-----------------+  |
       |  | Access #1 IP    | Access #2 IP    | Access #3 IP    |  |
       |  +-----------------------------------------------------+  |
       |                            MAMS User-Plane Protocol Stack |
       +-----------------------------------------------------------+

             Figure 1: MAMS User-Plane Protocol Stack [MAMS]

   Today, GRE is used [LWIPEP] [GRE]as the encapsulation protocol at
   the convergence layer to encode additional control information,
   e.g. Key, Sequence Number. However, there are two main drawbacks
   with this approach:

      o IP-over-IP tunnelling (required for GRE) leads to higher
        overhead especially for small packet;
      o It is difficult to introduce new control fields.

   For example, the overhead of IP-over-IP/GRE tunnelling with both
   Key and Sequence Number is 32 Bytes (20 Bytes IP header + 12 Bytes
   GRE header), which is 80% of a 40 Bytes TCP ACK packet;

   This document presents a light-weight GMA encapsulation protocol
   for the convergence layer. It supports three encapsulation
   methods: trailer-based IP encapsulation, header-based IP
   encapsulation, and non-IP encapsulation. Particularly, the IP
   encapsulation methods avoid IP-over-IP tunneling overhead (20
   Bytes), which is 50% of a 40 Bytes TCP ACK packet. Moreover, it
   introduces new control fields to support fragmentation and
   concatenation, which are not available in today's GRE-based
   solutions [LWIPEP] [GRE].

   GMA protocol SHALL only operate between endpoints that have been
   configured to operate with GMA through additional control messages
   and procedures, for example [MAMS]. Moreover, UDP or IPSec


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   tunneling MAY be used at the adaptation sublayer to protect GMA
   operation from intermediate nodes.

2. Conventions used in this document

   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.

3. Use Case

                         Multi-Access Aggregation

                    +---+                        +---+
                    | |A|--- LTE Connection -----|C| |
                    |U|-|                        |-|S| Internet
                    | |B|--- Wi-Fi Connection ---|D| |
                    +---+                        +---+
                   Client                Multi-Access Gateway

         A: The adaptation layer endpoint of the LTE connection
         resides in the client

         B: The adaptation layer endpoint of the Wi-Fi connection
         resides in the client

         C: The adaptation layer endpoint of the LTE connection
         resides in the Multi-Access Gateway, aka N-MADP (Network
         Multi-Access Data Proxy) in [MAMS]

         D: The adaptation layer endpoint of the Wi-Fi connection
         resides in the Multi-Access Gateway

         U: The convergence layer endpoint resides in the client

         S: The convergence layer endpoint resides in the Multi-
         Access Gateway

               Figure 2: GMA-based Multi-Access Aggregation

   As shown in Figure 2, a client device (e.g. Smartphone, Laptop,
   etc.) may connect to Internet via both Wi-Fi and LTE connections,
   one of which (e.g. LTE) may operate as the anchor connection, and
   the other (e.g. Wi-Fi) may operate as the delivery connection. The
   anchor connection provides the IP address and connectivity for

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   end-to-end Internet access, and the delivery connection provides
   additional path between client and Multi-Access Gateway for multi-
   access optimizations.

   For example, per-packet aggregation allows a single IP flow to use
   the combined bandwidth of the two connections. In another example,
   packets lost due to temporarily link outage may be retransmitted.
   Moreover, packets may be duplicated over multiple connections to
   achieve high reliability and low latency, and duplicated packets
   should be eliminated by the receiving side. Such multi-access
   optimization requires additional control information, e.g.
   Sequence Number, in each IP data packet, which can be supported by
   the GMA encapsulation protocol described in this document.

   The GMA protocol in this document is designed for multiple
   connections, but it may also be used when there is only one
   connection between two end-points. For example, it may be used for
   loss detection and recovery. In another example, it may be used to
   concatenate multiple small packets and reduce per packet overhead.

4. GMA Encapsulation Formats

   The GMA encapsulation protocols support the following three
   formats:

      o Trailer-based IP Encapsulation
      o Header-based IP Encapsulation
      o Header-based non-IP Encapsulation


          |<---------------------GMA PDU ----------------------->|
          +------------------------------------------------------+
          | IP hdr |        IP payload             | GMA Trailer |
          +------------------------------------------------------+
          |<------- GMA SDU (user payload)-------->|


             Figure 3: Trailer-based IP Encapsulation Format

   Figure 3 shows the trailer-based encapsulation GMA PDU (protocol
   data unit) format. A (GMA) PDU may carry one or multiple IP
   packets, aka (GMA) SDUs (service data unit), in the payload, or a
   fragment of the SDU.

   The Protocol Type field in the IP header of the GMA PDU MUST be
   changed to 114 (Any 0-Hop Protocol) [IANA] to indicate the


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   presence of the GMA trailer. The following three IP header fields
   SHOULD also be changed:

     o IP Length: add the length of "GMA Trailer" to the length of
        the original IP packet
     o Time To Live (TTL) or Hop-Limit (HL): set the HL field to "0"
        if the original IP packet is IPv6, and set the TTL field to "1"
        if the original IP packet is IPv4.
     o IP checksum: recalculate after changing "Protocol Type", "TTL
        or HL" and "IP Length"

   However, if UDP tunnelling is used at the adaptation layer to
   carry the GMA PDU, the above three IP header fields SHOULD remain
   unchanged, and the receiver will determine the GMA PDU length
   based on the UDP packet length.

   The GMA (Generic Multi-Access) trailer MUST consist of two
   mandatory fields: Flags and Next Header:

     o Next Header (1 Byte): the IP protocol type of the (first) SDU
        in a PDU, and it stores the value before it was overwritten to
        114.
     o Flags (2 Bytes): Bit 0 is the most significant bit (MSB), and
        Bit 15 is the least significant bit (LSB)
        + Checksum Present (bit 0): If the Checksum Present bit is set
        to 1, then the Checksum field is present;
        + Concatenation Present (bit 1): If the Concatenation Present
        bit is set to 1, then the PDU carries multiple SDUs, and the
        First SDU Length field is present;
        + Connection ID Present (bit 2): If the Connection ID Present
        bit is set to 1, then the Connection ID field is present;
        + Flow ID Present (bit 3): If the Flow ID Present bit is set
        to 1, then the Flow ID field is present;
        + Fragmentation Present (bit 4): If the Fragmentation Present
        bit is set to 1, then the PDU carry a fragment of the SDU and
        the Fragmentation Control field is present;
        + Delivery SN Present (bit 5): If the Delivery SN (Sequence
        Number) Present bit is set to 1, then the Delivery SN field is
        present and contains the valid information;
        + Flow SN Present (bit 6): If the Flow SN Present bit is set
        to 1, then the Sequence Number field is present;
        + Timestamp Present (bit 7): If the Timestamp Present bit is
        set to 1, then the Timestamp field is present;
        + TTL Present (bit 8): If the TTL Present bit is set to 1,
        then the TTL field is present;
        + Reserved (bit 9-12): set to "0" and ignored on receipt;
        + Version (bit 13~15): GMA version number, set to 0 for the
        GMA encapsulation protocol specified in this document.

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   The Flags field is at the end of the PDU, and the Next Header
   field is the second last. The Receiver SHOULD first decode the
   Flags field to determine the length of the GMA trailer, and then
   decode each optional field accordingly. The GMA (Generic Multi-
   Access) trailer MAY consist of the following optional fields:

     o Checksum (1 Byte): to contain the (one's complement) checksum
        sum of all the 8 bits in the trailer. For purposes of
        computing the checksum, the value of the checksum field is
        zero. This field is present only if the Checksum Present bit
        is set to one.
     o First SDU Length (2 Bytes): the length of the first IP packet
        in the PDU, only included if a PDU contains multiple IP
        packets. This field is present only if the Concatenation
        Present bit is set to one.
     o Connection ID (1 Byte): an unsigned integer to identify the
        anchor and delivery connection of the GMA PDU. This field is
        present only if the Connection ID Present bit is set to one.
        + Anchor Connection ID (MSB 4 Bits): an unsigned integer to
        identify the anchor connection
        + Delivery Connection ID (LSB 4 Bits): an unsigned integer to
        identify the delivery connection
     o Flow ID (1 Byte): an unsigned integer to identify the IP flow
        that a PDU belongs to, for example Data Radio Bearer (DRB) ID
        [LWIPEP] for a cellular (e.g. LTE) connection. This field is
        present only if the Flow ID Present bit is set to one.
     o Fragmentation Control (FC) (e.g. 1 Byte): to provide necessary
        information for re-assembly, only needed if a PDU carries
        fragments. This field is present only if the Fragmentation
        Present bit is set to one. Please refer to section 5 for its
        detailed format and usage.
     o Delivery SN (1 Byte): an auto-incremented integer to indicate
        the GMA PDU transmission order on a delivery connection.
        Delivery SN is needed to measure packet loss of each delivery
        connection and therefore generated per delivery connection per
        flow. This field is present only if the Delivery SN Present
        bit is set to one.
     o Flow SN (3 Bytes): an auto-incremented integer to indicate the
        GMA SDU (IP packet) order of a flow. Flow SN is needed for
        retransmission, reordering, and fragmentation. It SHALL be
        generated per flow. This field is present only if the Flow SN
        Present bit is set to one.
     o Timestamp (4 Bytes): to contain the current value of the
        timestamp clock of the transmitter in the unit of 1
        millisecond. This field is present only if the Timestamp
        Present bit is set to one.
     o TTL (1 Byte): to contain the TTL value of the original IP
        header if the GMA SDU is IPv4, or the Hop-Limit value of the

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        IP header if the GMA SDU is IPv6. This field is present only
        if the TTL Present bit is set to one.

   Figure 4 shows the GMA trailer format with all the fields present,
   and the order of the GMA control fields SHALL follow the bit order
   in the Flags field. For example, Bit 0 (the MSB) of the Flags
   field is the Checksum Present bit, and the Checksum field is the
   last in the trailer except of the two mandatory fields. Bit 1 is
   the Concatenation present bit, and the FSL field is the second
   last.

   The trailer-based IP encapsulation method SHOULD be used as long
   as implementation allows. However, if the GMA control fields can't
   be added at the end due to any reason, e.g. implementation
   constraints, one may use the header-based encapsulation.

 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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|     TTL       |                   Timestamp
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
                |                   Flow SN                     |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|  Delivery SN  |    FC         |   Flow ID     | Connection ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|      First SDU Length (FSL)   |   Checksum    |  Next Header  |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|         Flags                 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

                       Figure 4: GMA Trailer Format

          +-----------------------------------------------------+
          |GMA Header  | IP hdr |        IP payload             |
          +-----------------------------------------------------+
            Figure 5: Header-based Non-IP Encapsulation Format

   Figure 5 shows the header-based non-IP encapsulation format, and
   Figure 6 shows the GMA header format. Herein, "Flags" is moved to
   the front. Moreover, "TTL", "FSL", and "Next Header" are removed
   from the GMA control fields since the IP header fields of the GMA
   SDU remain unchanged during encapsulation. The order of other GMA
   control fields is the same as shown in Figure 4.

         +--------------------------------------------------+

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         |    Flags       |        GMA control fields       |
         +--------------------------------------------------+
                       Figure 6: GMA Header Format

   If the adaptation layer, e.g. UDP tunnelling, supports non-IP
   packet format, the GMA PDU format as shown in Figure 5 SHOULD be
   used without any modification.

   If the adaptation layer only supports IP packet format, the
   header-based IP encapsulation method MAY be used, and Figure 7
   shows its format. Herein, the IP header of the GMA SDU is moved to
   the front so that the GMA PDU becomes an IP packet, and the IP
   header fields of the GMA PDU SHOULD be changed in the same way as
   the trailered-based IP encapsulation method.

          +-----------------------------------------------------+
          |IP hdr | GMA Header  |             IP payload        |
          +-----------------------------------------------------+
              Figure 7: Header-based IP Encapsulation Format

   If the non-IP encapsulation method is configured, the GMA header
   SHOULD always be present. In comparison, the (header or trailer
   based) IP encapsulation (Figure 3 and 7) method may be used
   dynamically on per-packet basis, and setting the protocol type of
   the GMA PDU to "114" indicates the presence of GMA header (or
   trailer) in an IP packet.

   The GMA endpoints SHOULD configure the encapsulation method
   through control signalling or pre-configuration. For example, the
   "MX UP Setup Configuration Request" message as specified in Multi-
   Access Management Service[MAMS] includes "MX Convergence Method
   Parameters", which provides the list of parameters to configure
   the convergence layer. Here, a new "GMA encapsulation format"
   parameter SHOULD be included to indicate one of the following
   three GMA encapsulation formats:

      o Trailer-based IP Encapsulation (Figure 3)
      o Header-based non-IP Encapsulation (Figure 5)
      o Header-based IP Encapsulation (Figure 7)

5. Fragmentation

   The convergence layer MAY support fragmentation if a delivery
   connection has a smaller maximum transmission unit (MTU) than the
   original IP packet (SDU). The fragmentation procedure at the
   convergence sublayer is similar to IP fragmentation [RFC791] in


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   principle, but with the following two differences for less
   overhead:

     o The fragment offset field is expressed in number of fragments
     o The maximum number of fragments per SDU is 2^7 (=128)

   The Fragmentation Control (FC) field in the GMA trailer (or
   header) contains the following bits:

     o Bit #7: a More Fragment (MF) flag to indicate if the fragment
        is the last one (0) or not (1)
     o Bit #0~#6: Fragment Offset (in units of fragments) to specify
        the offset of a particular fragment relative to the beginning
        of the SDU

   A PDU carries a whole SDU without fragmentation if the FC field is
   set to all "0"s or the FC field is not present in the trailer.
   Otherwise, the PDU contains a fragment of the SDU.

   The Flow SN field in the trailer is used to distinguish the
   fragments of one SDU from those of another. The Fragment Offset
   (FO) field tells the receiver the position of a fragment in the
   original SDU. The More Fragment (MF) flag indicates the last
   fragment.

   To fragment a long SDU, the transmitter creates n PDUs and copies
   the content of the IP header fields from the long PDU into the IP
   header of all the PDUs. The length field in the IP header of PDU
   SHOULD be changed to the length of the PDU, and the protocol type
   SHOULD be changed to 114.

   The data of the long SDU is divided into n portions based on the
   MTU size of the delivery connection. The first portion of the data
   is placed in the first PDU. The MF flag is set to "1", and the FO
   field is set to "0". The i-th portion of the data is placed in the
   i-th PDU. The MF flag is set to "0" if it is the last fragment and
   set to "1" otherwise. The FO field is set to i-1.

   To assemble the fragments of a SDU, the receiver combines PDUs
   that all have the same Flow SN. The combination is done by placing
   the data portion of each fragment in the relative order indicated
   by  the  Fragment  Offset  in  that  fragment's  GMA  trailer  (or
   trailer). The first fragment will have the Fragment Offset set to
   "0", and the last fragment will have the More-Fragments flag set
   to "0".




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6. Concatenation

   The convergence sublayer MAY support concatenation if a delivery
   connection has a larger maximum transmission unit (MTU) than the
   original IP packet (SDU). Only the SDUs with the same client IP
   address, and the same Flow ID MAY be concatenated.

   If the (trailer or header based) IP encapsulation method is used,
   the First SDU Length (FSL) field SHOULD be included in the GMA
   trailer (or header) to indicate the length of the first SDU.
   Otherwise, the FSL field SHOULD not be included.

     +-----------------------------------------------------------+
     |IP hdr| IP payload    |IP hdr|   IP payload  | GMA Trailer |
     +-----------------------------------------------------------+
        Figure 8: Example of GMA PDU Format with Concatenation and
                      Trailer-based IP Encapsulation

   To concatenate two or more SDUs, the transmitter creates one PDU
   and copies the content of the IP header field from the first SDU
   into the IP header of the PDU. The data of the first SDU is placed
   in the first portion of the data of the PDU. The whole second SDU
   is then placed in the second portion of the data of the PDU
   (Figure 8). The procedure continues till the PDU size reaches the
   MTU of the delivery connection. If the FSL field is present, the
   IP length field of the PDU SHOULD be updated to include all
   concatenated SDUs and the trailer (or header), and the IP checksum
   field SHOULD be recalculated. However, if the non-IP encapsulation
   method is used, both the IP Length field and the checksum field of
   the PDU SHOULD remain unchanged, and the receiver will determine
   the GMA PDU length based on the UDP packet length.

   To disaggregate a PDU, if the (header or trailer based) IP
   encapsulation method is used, the receiver first obtains the
   length of the first SDU from the FSL field and decodes the first
   SDU. The receiver then obtains the length of the second SDU based
   on the length field in the second SDU IP header and decodes the
   second SDU. The procedure continues till no byte is left in the
   PDU. If the non-IP encapsulation method (Figure 5) is used, the IP
   header of the first SDU will not change during the encapsulation
   process, and the receiver obtains the length of the first SDU
   directly from its IP header.

   If a PDU contains multiple SDUs, the Flow SN field is for the last
   SDU, and the Flow SN of other SDU carried by the same PDU can be
   obtained according to its order in the PDU. For example, if the SN


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   field is 6 and a PDU contains 3 SDUs (IP packets), the SN is 4, 5,
   and 6 for the first, second, and last SDU respectively.

7. Security Considerations

   Security in a network using GMA should be relatively similar to
   security in a normal IP network. The GMA protocol at the
   convergence sublayer is a 0-hop protocol and relies on the
   security of the underlying network transport paths. When this
   cannot be assumed, appropriate security protocols (IPsec, DTLS,
   etc.) SHOULD be configured at the adaptation sublayer. On the
   other hand, packet filtering requires either that a firewall looks
   inside the GMA packet or that the filtering is done on the GMA
   endpoints. In those environments in which this is considered to be
   a security issue it may be desirable to terminate the GMA
   operation at the firewall.

   Local-only packet leak prevention (HL=0, TTL=1) SHOULD be on
   preventing the leak of the local-only GMA PDUs outside the "local
   domain" to the Internet or to another domain which could use the
   same IP protocol type, i.e. 114.

8. IANA Considerations

   This draft makes no requests of IANA

9. References

9.1. Normative References

   [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
             Requirement Levels", BCP 14, RFC 2119, DOI
             10.17487/RFC2119, March 1997, <https://www.rfc-
             editor.org/info/rfc2119>.

   [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
             2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174
             May 2017, <https://www.rfc-editor.org/info/rfc8174>.

9.2. Informative References

   [MAMS] S. Kanugovi, F. Baboescu, J. Zhu, and S. Seo "Multi-Access
             Management Services
             (MAMS)https://tools.ietf.org/rfc/rfc8743.txt

   [IANA]    https://www.iana.org/assignments/protocol-
             numbers/protocol-numbers.xhtml


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   [LWIPEP] 3GPP TS 36.361, "Evolved Universal Terrestrial Radio
             Access (E-UTRA); LTE-WLAN Radio Level Integration Using
             Ipsec Tunnel (LWIP) encapsulation; Protocol
             specification"

   [RFC791] Internet Protocol, September 1981

   [ATSSS] 3GPP TR 23.793, Study on access traffic steering, switch
             and splitting support in the 5G system architecture.

   [GRE] RFC 8157, Huawei's GRE Tunnel Bonding Protocol, May 2017

Authors' Addresses

   Jing Zhu

   Intel

   Email: jing.z.zhu@intel.com

   Satish Kanugovi

   Nokia

   Email: satish.k@nokia.com
























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