Internet Area Working Group S. Jiang
Internet-Draft Huawei
Intended status: Experimental 25 October 2021
Expires: 28 April 2022
Native Minimal Protocols with Flexibility at Edge Networks
draft-jiang-intarea-nmp-edge-00
Abstract
This document introduces a flexible native minimal protocol for fast
short packet transmission in edge networks, and can communicate with
IPv6 nodes through gateways.
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). 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 28 April 2022.
Copyright Notice
Copyright (c) 2021 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.
Jiang Expires 28 April 2022 [Page 1]
Internet-Draft NMP October 2021
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Requirements Notation . . . . . . . . . . . . . . . . . . . . 3
3. Overview . . . . . . . . . . . . . . . . . . . . . . . . . . 3
4. Protocol Design . . . . . . . . . . . . . . . . . . . . . . . 4
4.1. Packet Header Format . . . . . . . . . . . . . . . . . . 4
4.1.1. Data Packet Header Format . . . . . . . . . . . . . . 5
4.1.2. Control Packet Header Format . . . . . . . . . . . . 6
4.2. Control Messages . . . . . . . . . . . . . . . . . . . . 6
4.2.1. Address Request and Assignment Messages . . . . . . . 6
4.2.2. Address Lease Extension Messages . . . . . . . . . . 7
4.3. DNS Delegation Messages . . . . . . . . . . . . . . . . . 8
4.4. Functionalities of Gateway . . . . . . . . . . . . . . . 9
4.4.1. Address Management . . . . . . . . . . . . . . . . . 9
4.4.2. Address Translation . . . . . . . . . . . . . . . . . 9
5. Renumber Considerations . . . . . . . . . . . . . . . . . . . 10
6. Security Considerations . . . . . . . . . . . . . . . . . . . 10
7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 10
8. Normative References . . . . . . . . . . . . . . . . . . . . 10
Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 11
1. Introduction
TCP/IP protocol suites are adopted widely in different areas.
However, there are still numerous edge networks uses non-IP
technologies like ZigBee, BLE, CAN-bus, and Modbus for different
reasons (e.g., power-constrained devices, low transport rate media).
For such networks, application-layer gateways (or protocol
tranlators) are usually deployed to connect them with the Internet,
as shown in Figure 1.
Data
+- - - - - - - - - - - - - - - - - - - +
| |
V V
+--+ ZigBee +--+ TCP/IP +--+
| |<-------------->| |<--------------->| |
+--+ +--+ +--+
Non-IP Gateway TCP/IP
Terminal Terminal
Figure 1: Communication Architecture with Application Gateway
The application-layer translation mechanism MAY bring three main
drawbacks: 1. End-to-end security channel like IPSec or TLS is not
supported, a malicious gateway may manipulate data that is transmited
between two terminals. 2. Non-IP terminals are invisible to the TCP/
Jiang Expires 28 April 2022 [Page 2]
Internet-Draft NMP October 2021
IP network, which makes it hard to conduct QoS or OAM operations,
e.g., guaranteeing SLA of a specific non-IP terminal's traffic, or
"ping" a non-IP terminal. 3. When a non-IP terminal joins or one
leaves the network, corresponding rules SHOULD be configured on the
gateway, thus increasing operation costs (i.e., OPEX).
Therefore, it would be beneficial to make those non-IP terminals
adopt TCP/IP protocol suites, thus eliminating aforementioned
drawbacks. The Internet Protocol Version 6 (IPv6) is expected to
achieve the goal, however, it is challenging in some cases due to its
long address and header length (40 bytes in total). For instance, it
would consume more energy for power constrained terminals like IoT
devices, and would amplify flow completion time on low-rate transport
media or one with low MTU, thus decreasing user experiences.
To this end, this document proposes Native Minimal Protocol (NMP),
which is applied at edge networks by using minimal address length and
fields. Simultaneously, NMP eliminats the drawbacks that may brought
by application layer gateways.
2. Requirements Notation
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] and [RFC8174] when, and only when, they appear in all
capitals, as shown here.
3. Overview
NMP is an inter-node communication method and network layer protocol
for edge network with native addresses. It is designed for extreme
minimal IoT devices that communicates with each other and sometimes
with normal IP nodes. NMP nodes and NMP gateways use native short
addresses to identify themselves and use these addresses as source
and destination addresses for network communication. NMP data
packets and signaling packets are encapsulated in a simplified
manner. The NMP-IPv6 translation function is deployed on the gateway
to implement IP connections on the edge network. See Figure 2.
Jiang Expires 28 April 2022 [Page 3]
Internet-Draft NMP October 2021
+-----------+
+-----------+-IP network+-------------+
| +-----------+ |
| +-----------------+---------+ |
| | IP Header | Payload | |
| +-----------------+---------+ |
| |
+----+-----+ +-----+----+
| Gateway | | Gateway |
+----/+\---+ +----/+\---+
/ |+---------+---------+ / | \
/ || NMP hdr | Payload | / | \
/ |+---------+---------+ / | \
/ | \ +---------+---------+ | \
/ | \ | NMP hdr | Payload | | \
/ | \ +---------+---------+ | \
O O O O O O
Terminals Terminals
NMP domain A: NMP domain B:
Address length= m Address length= n
Only Support Extreme Simplified Control Messages within NMP Domain
Figure 2: Overview of Native Minimal Protocol
4. Protocol Design
4.1. Packet Header Format
The first bit at the beginning of the packet header indicates whether
the packet is a control message or a data packet. The basic format
is specified as follows Figure 3.
+----------------+---------------------+---------------------+
|Indicator(1 bit)|Data/Control Headers | Payload/MessageBody |
+----------------+---------------------+---------------------+
Figure 3: Basic Format of Native Minimal Protocol Packet
* Indicator one-bit indicator to indicate Data or Control packet
follows. 1 - control packet; 0 - data packet.
* Data/Control Headers Record the fileds of data packet header in
Section 4.1.1 or the control packet header in Section 4.1.2
Jiang Expires 28 April 2022 [Page 4]
Internet-Draft NMP October 2021
* Payload/MessageBody The payload of the data packet or message body
of a control packet
4.1.1. Data Packet Header Format
For data packet header, NMP uses bitmap with variable length to
indicate which in-line headers appear in the packet. The
specification is in Figure 4.
+----------------------+-------------------+
| Bitmap | In-line Headers |
| (7 bits, extensible) | (variable length) |
+----------------------+-------------------+
Figure 4: Data Packet Header Format
* Bitmap A variable-length bitmap with at least 7 bits is used to
indicate whether a NMP field is carried in a packet.The value 1
indicates that the packet carries this field and is located in the
following in-line headers field. The value 0 indicates that the
packet does not contain this field. The length of bitmap is
defined as follows.
+------------------+----------------------------+-----------------+
| bitmap format |number of bits for indicator|scope fo headers |
+------------------+----------------------------+-----------------+
| 1xx xxxx | 6 bits | header 1 ~ 6 |
+------------------+----------------------------+-----------------+
|01x xxxx xxxx xxxx| 13 bits | header 1 ~ 13 |
+------------------+----------------------------+-----------------+
* In-line Headers The headers in NMP packet. Each header
corresponds to a position in preceding bitmap.
Jiang Expires 28 April 2022 [Page 5]
Internet-Draft NMP October 2021
+--------+----------------+---------------+
| Bitpos | Header Name | Header Length |
+--------+----------------+---------------+
| 1 | Destination | Variable |
+--------+----------------+---------------+
| 2 | Source | Variable |
+--------+----------------+---------------+
| 3 | Next Header | 8 bit |
+--------+----------------+---------------+
| 4 | Payload Length | Variable |
+--------+----------------+---------------+
| 5 | Checksum | 8 bit |
+--------+----------------+---------------+
| 6 | DNS | 0 bit |
+--------+----------------+---------------+
| 7 ~ 13 | Reserved | / |
+--------+----------------+---------------+
4.1.2. Control Packet Header Format
+----------------------+-------------------+
| Type | Checksum |
| (7 bits) | (8 bits) |
+----------------------+-------------------+
Figure 5: Control Packet Header Format
* Type This filed carries value to indicate the type of this control
message.
* Checksum The checksum is the 8-bit one's complement of the one's
complement sum of the entire control message, starting with the
message type field, and prepended with a "1" of indicator header
fields, as specified in Section 4.1. For computing the checksum,
the checksum field is first set to zero.
4.2. Control Messages
4.2.1. Address Request and Assignment Messages
A NMP host broadcasts an Address Request (AR) message to request an
address from the gateway of the NMP domain. The gateway sends an
Address Assignment (AA) message to the host to configure the host's
NMP address. #### Format of Address Request The value of the message
Type is 0b000 0001. The message body is defined as follows.
Jiang Expires 28 April 2022 [Page 6]
Internet-Draft NMP October 2021
+-------------------+-----------+
| ID length (8 bits) | Host ID |
+-------------------+-----------+
* ID length Length of this field is 1 octet. This header specifies
the length of the Host ID field, in octets.
* Host ID Indicates the identifier of the host that accesses the NMP
network. The identifier can be a MAC address or another globally
unique identifier.
4.2.1.1. Format of Address Assignment
The value of the message Type is 0b000 0010. The message body is
defined as follows.
+-------------------+---------+---------+-----------+--------+
|NMP Address Length | NMP | Gateway | ID length | Host ID|
| 8 bits | Address | Address | (8 bits) | |
+-------------------+---------+---------+-----------+--------+
* NMP Address Length Length of this field is 1 octet. This
parameter specifies the length of the NMP address used in the
local NMP domain.
* NMP Address Network layer address assigned to the host node. The
length is specified by the NMP Address Length field.
* Gateway Address Network layer address of the gateway. The length
is the same as length of NMP Address
* ID length Length of this field is 1 octet. This header specifies
the length of the Host ID field, in octets.
* Host ID Indicates the identifier of the host that accesses the NMP
network. The identifier can be a MAC address or another globally
unique identifier.
4.2.2. Address Lease Extension Messages
To reduce the complexity of the NMP host, the gateway records the
lease information of each NMP address. When the lease of a host
address expires, the gateway sends a Renewal Challenge message to the
host and waits for an response from the host. If a Renewal Response
message is received from the host, the lease information is updated
based on the preconfigured strategy. Otherwise, the gateway releases
the NMP address.
Jiang Expires 28 April 2022 [Page 7]
Internet-Draft NMP October 2021
4.2.2.1. Renewal Challenge Message
The value of the message Type is 0b000 0011. The message body is
defined as follows.
+-------------------+---------+-----------+--------+
|NMP Address Length | NMP | ID length | Host ID|
| 8 bits | Address | (8 bits) | |
+-------------------+---------+-----------+--------+
* NMP Address Length Length of this field is 1 octet. This
parameter specifies the length of the NMP address used in the
local NMP domain.
* NMP Address Network layer address assigned to the host node. The
length is specified by the NMP Address Length field.
* ID length Length of this field is 1 octet. This header specifies
the length of the Host ID field, in octets.
* Host ID Indicates the identifier of the host that accesses the NMP
network. The identifier can be a MAC address or another globally
unique identifier.
4.2.2.2. Renewal Response Message
The value of the message Type is 0b000 0100. The message body is
defined in Section 4.2.2.1.
4.3. DNS Delegation Messages
Many IoT products are written into the domain name of the IoT service
platform when they are manufactured. The IP address of the server
needs to be obtained through the DNS to establish communication.
Within the NMP domain, some modifications are required to traditional
DNS messages in [RFC1035]. The NMP host sends a DNS query packet to
the gateway. The Indicator field of the packet is set to 0, and the
DNS bit of the bitmap is set to 1. Destination of the packet is set
to NMP address of gateway. When the gateway receives the packet, it
directly translates the network layer information and sends a regular
DNS packet to the DNS server configured on the gateway.
NMP is replaced by IPv6 protocol after the gateway. The source
address is changed to 'IPv6 address prefix stored in the gateway +
padding bit + NMP address', the destination address is changed to the
DNS server address configured on the gateway, and the payload
information remains unchanged.
Jiang Expires 28 April 2022 [Page 8]
Internet-Draft NMP October 2021
When the DNS response packet sent by the DNS server reaches the
gateway, the gateway resolves the response packet and allocates an
available NMP address to the destination IPv6 address. The NMP
address is used as an in-network mirror of the IPv6 address and
replaces the target address in the DNS response packet. Then, the
gateway sends the DNS response packet to the NMP host.
The header format of an DNS delegation message is defined as follows.
For details about the format of a DNS message body, see [RFC1035].
+-+---------+---------+---------+---------+------------+-----------+
|0| 1111111 | gw addr | NMP src | Nxt Hdr | pld length | hchecksum |
+-+---------+---------+---------+---------+------------+-----------+
| UDP header | |
+---------------------+ +
| |
| DNS message body defined in RFC 1035 |
| |
+------------------------------------------------------------------+
4.4. Functionalities of Gateway
4.4.1. Address Management
The NMP gateway initializes the NMP address pool based on the network
configuration and assigns an address to itself. This address is used
as the default gateway by the hosts in the domain.
Intra-domain address management functionaliteis includes: * intra-
domain host address allocation The gateway listens to the NMP address
request message, allocates the corresponding NMP address based on the
message content, generates an address assignment message, and returns
the message to the host. The assigned addresses must meet the
uniqueness requirements within the NMP domain. * intra-domain host
address life cycle management The gateway manages the validity period
of NMP addresses. The lease renewal challenge mechanism is used to
renew or release host addresses.
4.4.2. Address Translation
The NMP address space can be mapped to specific subspaces of IPv6
address space. When traffic is destinated to a destination outside
the domain, the gateway translates the host address (source address)
in the domain into an IPv6 address. For details about the
translation method, see TBD.
Jiang Expires 28 April 2022 [Page 9]
Internet-Draft NMP October 2021
For traffic from outside of the domain, determines whether the
destination is within the domain. If the destination is within the
domain, then the gateway translates the destination address to the
corresponding NMP address.
5. Renumber Considerations
The NMP renumbering problem is not beyond the scope of [RFC6866] and
[RFC7010], [RFC5887].
6. Security Considerations
Checksum is used to defend against malformed packets and null packet
attacks caused by network bit errors. ICMPv6 uses a 16-bit checksum.
NMP uses an 8-bit checksum to reduce the computing load on the host
side and improve the packet encapsulation efficiency. This leads to
a higher probability of network errors.
7. IANA Considerations
If NMP is running on Ethernet, a new Ethtype is required. In
addition to Ethernet, other link-layer protocols that need to carry
multiple upper-layer protocols need to assign specific identifiers to
NMP to instruct devices to process network-layer packets according to
this document.
This document requires to define new registry for NMP control message
types, six of which are defined in this document.
8. Normative References
[RFC1035] Mockapetris, P., "Domain names - implementation and
specification", STD 13, RFC 1035, DOI 10.17487/RFC1035,
November 1987, <https://www.rfc-editor.org/info/rfc1035>.
[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>.
[RFC5887] Carpenter, B., Atkinson, R., and H. Flinck, "Renumbering
Still Needs Work", RFC 5887, DOI 10.17487/RFC5887, May
2010, <https://www.rfc-editor.org/info/rfc5887>.
[RFC6866] Carpenter, B. and S. Jiang, "Problem Statement for
Renumbering IPv6 Hosts with Static Addresses in Enterprise
Networks", RFC 6866, DOI 10.17487/RFC6866, February 2013,
<https://www.rfc-editor.org/info/rfc6866>.
Jiang Expires 28 April 2022 [Page 10]
Internet-Draft NMP October 2021
[RFC7010] Liu, B., Jiang, S., Carpenter, B., Venaas, S., and W.
George, "IPv6 Site Renumbering Gap Analysis", RFC 7010,
DOI 10.17487/RFC7010, September 2013,
<https://www.rfc-editor.org/info/rfc7010>.
[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>.
Author's Address
Sheng Jiang
Huawei Technologies
Beiqing Road, Haidian District
Beijing
100095
China
Email: jiangsheng@huawei.com
Jiang Expires 28 April 2022 [Page 11]