Internet DRAFT - draft-deng-softwire-aplusp-experiment-results
draft-deng-softwire-aplusp-experiment-results
Internet Engineering Task Force X.Deng
Internet Draft M.Boucadair
Intended status: Informational France Telecom
Expires: September 2, 2012 Y.Lee
Comcast
X.Huang
Q.Zhao
BUPT
March 1, 2012
Implementing A+P in the provider's IPv6-only network
draft-deng-softwire-aplusp-experiment-results-02.txt
Abstract
This memo describes an implementation of A+P in a provider's IPv6-
only network. It provides details of the implementation, network
elements, configurations and test results as well. Besides
traditional port range A+P, a scattered port sets flavor of A+P is
also implemented to verify feasibility of offering non-continuous
port sets with A+P approach.
The test results consist of the application compatibility test, UPnP
1.0 extensions and UPnP 1.0 friendly port allocation for A+P, port
usage and BitTorrent behaviors with A+P.
This memo focuses on the IPv6 flavor of A+P.
Status of this Memo
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provisions of BCP 78 and BCP 79.
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and may be updated, replaced, or obsoleted by other documents at any
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material or to cite them other than as "work in progress."
This Internet-Draft will expire on September 2, 2012.
Copyright Notice
Copyright (c) 2012 IETF Trust and the persons identified as the
document authors. All rights reserved.
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Table of Contents
1. Introduction ................................................ 3
2. Terminology ................................................. 3
3. Implementation environment ................................... 4
3.1. Environment Overview .................................... 4
3.2. Implementation and Configuration of A+P ................. 5
3.2.1. IPv4-Embedded IPv6 Address Format For A+P CPE ...... 6
3.2.2. DHCPv6 Configurations .............................. 6
3.2.3. Avoiding Fragmentation ............................. 6
3.3. Implementing non-continuous Port Sets for A+P ........... 7
3.3.1. Non-continuous Port Sets allocation mechanism ...... 7
3.3.2. IPv4-Embedded IPv6 Address Format for Non-continuous
Port Sets A+P CPE ....................................... 10
3.3.3. Customize a non-continuous Ports Set A+P NAT ...... 11
4. Application Tests and Experiments in A+P Environment ........ 12
4.1. A+P Impacts on Applications ............................ 12
4.2. UPnP extension experiment
.............................. 13
4.2.1. UPnP 1.0 extension ................................ 13
4.2.2. UPnP 1.0 friendliness attempts .................... 14
4.3. Port Usage of Applications ............................. 16
4.4. BitTorrent Behaviour in A+P ............................ 17
5. Security Considerations .................................... 18
6. IANA Considerations ........................................ 18
7. Conclusion ................................................. 18
8. References ................................................. 19
8.1. Normative References ................................... 19
8.2. Informative References ................................. 19
9. Additional Authors ......................................... 20
10. Acknowledgments ........................................... 20
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1. Introduction
A+P [RFC6346] is a technique to share IPv4 addresses over IPv6-only
network without requiring a NAT function in the provider's network.
The main idea of A+P is borrowing some bits from the port number in
the TCP/UDP header to identify the end point. Those port numbers
assigned to the end point will be used by IPv4 applications. A+P can
facilitate network migration to IPv6-only while continue to offer
IPv4 connectivity to customers by tunneling IPv4 packets over IPv6-
only network.
We implemented A+P in a residential ADSL access network, where IPv6-
only access network is provided over PPPoE. In this memo, we first
describe the implementation environment including A+P IPv6 prefix
format and network elements configurations, then we describes the
test results. In particular, this memo focuses on the SMAP function
implementation specified in [RFC6346].
For more application test results in A+P environment, please refer to
[draft-boucadair-behave-bittorrent-portrange-02] and [draft-
boucadair-port-range-01].
2. Terminology
This memo uses the following terms:
o PRR: Port Range Router
o A+P CPE: A+P aware Customer Premise Equipment
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3. Implementation environment
3.1. Environment Overview
public
addresses +----------+
realm | PRR |
| |
=== +----------+
IPv4 ^ ^ ^
| | |
| v v
| +--------------+
| | PPPoE/DHCPv6 |
over | | Server |
| +--------------+
| === ^ ^
| IPv6 ^ | |
| over | | |
IPv6 | PPPoE | | |
V v | |
=== === v v
^ +----------+
| | A+P |
| | CPE |
| +----------+
Private | ^ ^
RFC1918 | | |
realm | v v
| +----------+
| | Host |
| | |
V +----------+
Figure 1 : Implementation Environment
We developed both A+P CPE function and Port Range Router (PRR)
function on Linux. A+P CPE function was implemented on Linksys
WRT54GS router running OpenWRT 2.6.32. PRR function was implemented
on standard Intel based server. Figure 1 shows the high-level network
diagram of the test environment.
Figure 2 shows the configuration of A+P CPE. IPv6 prefix was
provisioned over PPPoE to CPE by a DHCPv6 server. In addition, it
also offered A+P parameters via DHCPv6 options defined in [draft-
boucadair-dhcpv6-shared-address-option].
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+--------+------------+-------+-----+------------+-----------+------+
| Model | CPU Speed | Flash | RAM | Wireless | Wireless | Wired|
| | (MHz) | (MB) | (MB)| NIC | Standard | Ports|
+--------+---------- -+-------+-----+------------+-----------+------+
| Linksys| 200 | 8 | 32 | Broadcom | 11g | 5 |
| WRT54GS| | | |(integrated)| | |
+--------+------------+-------+-----+------------+-----------+------+
Figure 2 :Parameters of A+P CPE
3.2. Implementation and Configuration of A+P
A+P CPE uses Netfilter framework to implement the port-set restricted
NAT. Port set restricted NAT operation was done by iptables rules.
After the port restricted NAT operation, IPv4 packets were sent to a
TUN interface which was a virtual network interface in Linux. The TUN
interface is a virtual interface that performs the IPv4-in-IPv6
function. Using the IPv4-Embedded IPv6 address format defined in
section 3.2.1, an IPv4-in-IPv6 function is performed by the TUN
interface handler.
PRR bridges the IPv6 access network to the IPv4 Internet. It contains
two main functions: 1) IPv4-in-IPv6 encapsulation/decapsulation;
Similar to A+P CPE, PRR implementation leveraged the virtual TUN
driver handler for IPv4-in-IPv6 function. 2) Destination IPv4 address
and layer 4 port based routing function is responsible for routing
the IPv4 traffic originated from the IPv4 Internet to the Port Range
restricted A+P CPE. The goal of PRR is to deliver the IPv4 packet to
the A+P CPE that was assigned with the port number used in the
destination port in the layer 4 header. Since PRR delivers the IPv4
packet over IPv4-in-IPv6 tunnel, PRR can embed the IPv4 address and
port number in the IPv6 address. The IPv4-Embedded IPv6 address is
used to uniquely identify the A+P CPE. Details of how to construct
the IPv4-Embedded IPv6 address format is defined in Section 3.2.1.
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3.2.1. IPv4-Embedded IPv6 Address Format For A+P CPE
|31bits|1bit| 32bits|8 bits|16bits|4bits|1bit|1bit|1bit|1bit|32 bits|
+------+----+-------+------+------+-----+----+----+----+----+-------+
|A+P |flag|Public | EUI64| port |Port |flag|flag|flag|flag|Public |
|Prefix| 0 |IPv4 | | Range|Range| 1 | 2 | 3 | 4 |IPv4 |
| | |Address| | |Size | | | | |Address|
+------+----+-------+------+------+-----+----+----+----+----+-------+
Figure 3 :IPv4-Embedded IPv6 address format
flag0: Is this address used by CPE or PRR?
flag1: Is address shared?
flag2: Is length of invariable present?
flag3: Is port range identifying sub network?
flag4: Reserved?
To facilitate other parties who are also interested in testing A+P
solution, we are considering to release this A+P implementation under
open source license. For more implementation details, please refer to
[Implementing A+P].
3.2.2. DHCPv6 Configurations
DHCPv6 options defined in [draft-boucadair-dhcpv6-shared-address-
option] were implemented. These options allow configuring a shared
address and a port range using a DHCPv6 option.
3.2.3. Avoiding Fragmentation
Normally the host TCP/IP protocol stack uses TCP protocol stack uses
Maximum Segment Size (MSS) option and/or Path Maximum Transmission
Unit Discovery (PMTUD) to determine the MTU.
However adding the IPv6 Header and the PPPoE header to the IPv4
packet may exceed the maximum MTU of the wire and consequently
results in IP fragmentation.
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One solution is to add a rule to iptables on A+P CPE to modify the
MSS value in TCP SYN and SYN-ACK. This can be done using command
"iptables -t mangle -A FORWARD -p tcp --tcp-flags SYN,RST SYN -j
TCPMSS --set-mss DESIRED_MSS_VALUE". The DESIRED_MSS_VALUE is set to
exclude IPv4 header, TCP header, IPv6 header and PPPoE header length.
3.3. Implementing non-continuous Port Sets for A+P
3.3.1. Non-continuous Port Sets allocation mechanism
[I-D.ietf-intarea-shared-addressing-issues] states that a bulk of
incoming ports can be reserved as a centralized resource shared by
all subscribers using a given restricted IPv4 address. We could
distribute a range of continuous ports to each subscriber. This may
create security concerns such as blind attack. An alternative would
be to assign a bulk of non-continuous random ports to each
subscriber. The following session would describe the implementation
of non-continuous port-set.
Note that the non-continuous port-set allocation mechanism described
here is just one possible solution to implement non-continuous port
provisioning. The implementation itself is to achieve two goals: 1)
Proving of feasibility of non-continuous port-set with A+P approach;
2) Evaluating UPnP 1.0 compatibility with non-continuous port-set.
Experiment results are provided in Section 4.2.2. Given a port-set
size N, log2(N) bits are randomly chosen as subscribers
identification bits(S-bit). S-bit must be chosen between 1st and 16th
bits. For example: if sharing ration is 1:32, each subscriber will
have five S-bits. Figure 4 shows an example of 5 S-bits (2nd, 5th,
7th, 9th and 11th) for a subscriber.
Subscriber ID pattern is formed by setting all the S-bits to 1 and
other trivial bits to 0. Figure 5 illustrates an example of
subscriber ID pattern based on S-bits example in Figure 4.
Note that the subscriber ID pattern must be identical for each
subscriber that shares the same IPv4 address.
Subscribers ID value is assigned by setting subscriber ID pattern
bits (s bits shown in figure 4) to a unique customer value to
identify each customer and setting other trivial bits to 1. An
example of subscriber ID value, having a subscriber ID pattern shown
in the figure 5 and a customer value 0, is shown in the figure 6.
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|1st |2nd |3rd |4th |5th |6th |7th | 8th|
+----+----+----+----+----+----+----+----+
| 0 | s | 0 | 0 | s | 0 | s | 0 |
+----+----+----+----+----+----+----+----+
|9th |10th|11th|12th|13th|14th|15th|16th|
+----+----+----+----+----+----+----+----+
| s | 0 | s | 0 | 0 | 0 | 0 | 0 |
+----+----+----+----+----+----+----+----+
Figure 4 : An S-bit selection example (on a sharing ration 1:32
address).
|1st |2nd |3rd |4th |5th |6th |7th | 8th|
+----+----+----+----+----+----+----+----+
| 0 | 1 | 0 | 0 | 1 | 0 | 1 | 0 |
+----+----+----+----+----+----+----+----+
|9th |10th|11th|12th|13th|14th|15th|16th|
+----+----+----+----+----+----+----+----+
| 1 | 0 | 1 | 0 | 0 | 0 | 0 | 0 |
+----+----+----+----+----+----+----+----+
Figure 5 : A subscriber ID pattern example (on a sharing ration 1:32
address).
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|1st |2nd |3rd |4th |5th |6th |7th | 8th|
+----+----+----+----+----+----+----+----+
| 1 | 0 | 1 | 1 | 0 | 1 | 0 | 1 |
+----+----+----+----+----+----+----+----+
|9th |10th|11th|12th|13th|14th|15th|16th|
+----+----+----+----+----+----+----+----+
| 0 | 1 | 0 | 1 | 1 | 1 | 1 | 1 |
+----+----+----+----+----+----+----+----+
Figure 6 : A subscriber ID value example (customer value: 0)
Subscriber ID pattern and subscriber ID value together uniquely
define a restricted port set (Non-contiguous port sets or a
contiguous port range, depends on Subscriber ID pattern and
subscriber ID value) on a restricted IP address.
Pseudo-code shown in the Figure 7 describes how to use subscriber ID
pattern and subscriber ID value to implement a random ephemeral port
selection function within the defined restricted port sets on a
customer NAT.
do{
restricted_next_ephemeral = (random()|subscriber_ID_pattern)
& subscriber_ID_value;
if(five-tuple is unique)
return restricted_next_ephemeral;
}
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Figure 7 : Random ephemeral port selection within the restricted port
set
3.3.2. IPv4-Embedded IPv6 Address Format for Non-continuous Port Sets
A+P CPE
|31bits|1bit| 32bits|8bits|16bits |4bits|1bit|1bit|1bit|1bit|32bits|
+------+----+-------+------+------+-----+----+----+----+----+-------+
|A+P |flag|Public | EUI64|SID_ |Reser|flag|flag|flag|flag|Public |
|Prefix| 0 |IPv4 | |Value |-ved | 1 | 2 | 3 | 4 | IPv4 |
| | |Address| | | | | | | |Address|
+------+----+-------+------+------+-----+----+----+----+----+-------+
Figure 8 :IPv4-Embedded IPv6 address format
SID Value: Subscriber_ID_Value, which is unique for per subscriber
sharing a given restricted IPv4 address. and has been allocated to
each subscriber.
flag0: Is this address used by CPE or PRR?
flag1: Is address shared?
flag2: Is length of invariable present?
flag3: Is port range identifying sub network?
flag4: Reserved?
To support non-continuous port-set, PRR maintains a mapping table
which contains the pairs of restricted IPv4 address and it's
Subscriber ID Pattern. To form an IPv6 destination address for
incoming packet, PRR could find the right SID Pattern according to a
destination IPv4 address, and then apply a simple operation shown in
the figure 9.
SID_Value = Destination_Port | (~SID_Pattern);
Figure 9 :PRR calculates SID Value
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3.3.3. Customize a non-continuous Ports Set A+P NAT
On a Linux kernel 2.6.32.36, only one line of linux kernel code was
Changed to implement this feature. Figure 10 shows the change. Figure
11 show the IPtables commands required in the PRR. The beginning of
port range changed to SID_Value and the ending of the port range
changed to SID_Pattern.
bool nf_nat_proto_unique_tuple(...)
...
//The Original code:
//*portptr = htons(min + off % range_size);
// was changed to:
*portptr = htons((ntohs(off) | min ) & max );
...
Figure 10:Function of finding a unique 5-tuple for a non-
continuousport sets A+P NAT
iptables -t nat -A POSTROUTING -o eth0 -p tcp -j SNAT --to-source
a.b.c.d: SID_Value-SID_Pattern --random
iptables -t nat -A POSTROUTING -o eth0 -p udp -j SNAT --to-source
a.b.c.d: SID_Value-SID_Pattern --random
Figure 11: IPtables commands for a non-continuousports set A+P NAT
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4. Application Tests and Experiments in A+P Environment
A set of well-known applications was tested. The tests compared A+P
over IPv6 and simple A+P without encapsulation on a pain IPv4
network. The test results showed that both share the same impacts
[draft-boucadair-port-range-01]. Web browsing (IE and Firefox), Email
(Outlook), Instant message(MSN),Skype, Google Earth work normally
with A+P. For more details, please refer to [draft-boucadair-port-
range-01].
4.1. A+P Impacts on Applications
+------------------+--------------------------------------+
| Application | A+P impacts |
+------------------+--------------------------------------+
| IE | None |
+------------------+--------------------------------------+
| Firefox | None |
+------------------+--------------------------------------+
| FTP(Passive mode)| None |
+------------------+--------------------------------------+
| FTP(Active mode) | require opening port forwarding |
| | |
+------------------+--------------------------------------+
| Skype | None |
+------------------+--------------------------------------+
| Outlook | None |
+------------------+--------------------------------------+
| Google Earth | None |
+------------------+--------------------------------------+
| BitComet | UPnP extensions may be required, when|
| | listening port is out of A+P range; |
| | other minor effects(see Section 4.4) |
+------------------+--------------------------------------+
| uTorrent | UPnP extensions may be required, when|
| | listening port is out of A+P range; |
| | other minor effects(see Section 4.4) |
+------------------+--------------------------------------+
| Live Messenger | None |
+------------------+--------------------------------------+
Figure 12: A+P impacts on applications
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P2P (Peer-to-Peer) applications using specific port for inbounding
connection are likely to fail, because the specific ports may not be
available for that A+P subscriber. Some UPnP extensions may be
required to make P2P applications work properly with A+P. Other minor
effects of A+P are discussed in Section 4.4.
4.2. UPnP extension experiment
4.2.1. UPnP 1.0 extension
To make P2P application work properly with port restricted NAT , we
have designed extensions including new variables, new error codes as
well as new actions to UPnP 1.0, and have them implemented with
[Emule], [open source UPnP SDK 1.0.4 for Linux] and [Linux UPnP IGD
0.92].
In figure 5, a new error code is proposed for the existing
"AddPortMapping" action to explicitly indicate the situation that the
requested external port is out of range.
+----------+-----------------------+-----------------------------+
| ErrorCode| errorDescription | Description |
+----------+-----------------------+-----------------------------+
| 728 |ExternalPortOutOfRange | The external port is out |
| | | of the port range assigned |
| | | to this external interface |
+----------+-----------------------+-----------------------------+
Figure 13:New ErrorCode for "AddPortMapping" action
New state variables have been introduced to reflect the valid port
range. The definitions of these state variables are shown in figure
6.
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+-------------+-------+------+----------+---------+-------+
|Variable |Req. or| Data | Allowed | Default | Eng. |
| Name | Opt.| Type | Value | Value | Units |
+-------------+-------+------+----------+---------+-------+
|PortRangeLow | O | ui2 | >=0 | 0 | N/A |
+-------------+-------+------+----------+---------+-------+
|PortRangeHigh| O | ui2 | <=65535 | 65535 | N/A |
+-------------+-------+------+----------+---------+-------+
Figure 14: New state variables for port range
Correspondingly, new actions, GetPortRangeLow and GetPortRangeHigh,
defined to retrieve port range information are illustrated in figure
7. An IP address should be provided as argument to invoke the new
actions, for the port range is associated with a specific IP address.
+----------------+-----------------------+----+--------------------+
| Action Name | Argument |Dir.| Related |
| | | | StateVariable |
+----------------+-----------------------+----+--------------------+
|GetPortRangeLow | NewExternal IPAddress | IN | ExternalIPAddress |
| +-----------------------+----+--------------------+
| | NewPortRange Low | OUT| PortRangeLow |
+----------------+-----------------------+----+--------------------+
|GetPortRangeHigh| NewExternal IPAddress | IN | ExternalIPAddress |
| +-----------------------+----+--------------------+
| | NewPortRange High | OUT| PortRangeHigh |
+----------------+-----------------------+----+--------------------+
Figure 15: New actions for port range
Please refer to [UPnP Extension] for more details of UPnP extension
experiment in A+P.
4.2.2. UPnP 1.0 friendliness attempts
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+-------------------+----------------------------------------------+
| Application | Behaviors |
| | |
+-------------------+----------------------------------------------+
| Microtorrent v2.2 | call GetSpecificPortMapping by incremental by|
| | 1 each time, |
| (also known as | until find an external port available, and |
| uTorrent) | then call AddPortMapping,or return error |
| | after five failures |
+-------------------+----------------------------------------------+
| Emule v0.50a | call AddPortMapping, after finding the |
| | external port not available return error |
| | |
+-------------------+----------------------------------------------+
| Azureus v4.6.0.2 | call AddPortMapping, after finding the |
| | external port not available, try the same |
| | port 5 more times by call AddPortMapping, |
| | then return error |
|-------------------+----------------------------------------------+
| Shareazav2.2.5.7 | call GetSpecificPortMapping, after finding |
| | the external port not available, return error|
| | without issuing AddPortMapping |
+-------------------+----------------------------------------------+
Figure 16 UPnP 1.0 applications behaviors of asking for an external
port
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The Behaviors test results in the previous figure shows that if a
request of external port failed, some UPnP 1.0 applications, namely
Microtorrent v2.2 and Azureus v4.6.0.2 attempt to issue (at most) 4
more times request until succeed. With each external port request
attempts, the desired external port is incremented by 1 of the
previous requested external port.
Hence, allocating port sets in a way that each A+P subscriber has sub
sets interval less than 5 would make some UPnP 1.0 applications
succeed in 5 times retrying. For example, In case a Subscriber ID
Pattern 0x02 that makes 2 customers sharing one IPv4 address, and
customer 1 have the available ports
{ 0,1 | 4,5 | 8,9 |12,13|....} while customer 2 have the available
ports:
{ 2,3 | 6,7 | 10,11|14,15|....}
Microtorrent v2.2 and Azureus v4.6.0.2 would be compatible with port
restriction feature of A+P.
IGD:1 is known to be broken in shared address environment [RFC6269];
IGD:2 mitigates the issues encountered in IGD:1. The efforts,
documented in section 4.2, were attempts before standardization of
IGD:2.
4.3. Port Usage of Applications
Port consumptions of applications not only impact the deployment
factor (i.e., port range size) for A+P solution but also play an
important role in determining the port limitation of per customer on
AFTR for Dual-Stack Lite.
Therefore we have also developed and deployed a Service Probe in our
IPv6 network, which use IPv6 TCP socket to ask A+P CPE for NAT
session usage, and store A+P NAT statistics in a Mysql database for
further analysis of application behaviours in terms of port and
session consumptions.
In figure 8, the maximum port usage of each application is the peak
number of port consumption per second during the whole communication
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process. The duration time represents the total time from the first
NAT binding entry being established to the last one being destroyed.
+-----------+--------------------------+--------------+----------+
|Application| Test case | Maximum | Duration |
| | | port usage | (seconds)|
+-----------+--------------------------+--------------+----------+
| | browsing a news website | 20-25 | 200 |
| IE +--------------------------+--------------+----------+
| | browsing a video website | 40-50 | 337 |
+-----------+--- ----------------------+--------------+----------+
| | browsing a news website | 25-30 | 240 |
| Firefox +--------------------------+--------------+----------+
| | browsing a video website | 80-90 | 230 |
+-----------+--------------------------+--------------+----------+
| | browsing a news website | 50-60 | 340 |
| Chrome +--------------------------+--------------+----------+
| | browsing a video website | 80-90 | 360 |
+-----------+--------------------------+--------------+----------+
| Android | browsing a news website | 40-50 | 300 |
| Chrome +--------------------------+--------------+----------+
| | browsing a video website | under 10 | 160 |
+-----------+--------------------------+--------------+----------+
| Google | locating a place | 30-35 | 240 |
| Earth | | | |
+-----------+--------------------------+--------------+----------+
| Android | | | |
| Google | locating a place | 10-15 | 240 |
| Earth | | | |
+-----------+--------------------------+--------------+----------+
| Skype | make a call | under 10 | N/A |
+-----------+--------------------------+--------------+----------+
| BitTorrent| downloading a file | 200 | N/A |
+-----------+--------------------------+--------------+----------+
Figure 17: Port usage of applications
4.4. BitTorrent Behaviour in A+P
[draft-boucadair-behave-bittorrent-portrange] provides an exhaustive
testing report about the behaviour of BiTtorrent in an A+P
architecture. [draft-boucadair-behave-bittorrent-portrange] describes
the main behavior of BitTorrent service in an IP shared address
environment. Particularly, the tests have been carried out on a
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testbed implementing [ID.boucadair-port-range] solution. The results
are, however, valid for all IP shared address based solutions.
Two limitations were experienced. The first limitation occurs when
two clients sharing the same IP address want to simultaneously
retrieve the SAME file located in a SINGLE remote peer. This
limitation is due to the default BitTorrent configuration on the
remote peer which does not permit sending the same file to multiple
ports of the same IP address. This limitation is mitigated by the
fact that clients sharing the same IP address can exchange portions
with each other, provided the clients can find each other through a
common tracker, DHT, or Peer Exchange. Even if they can not, we
observed that the remote peer would begin serving portions of the
file automatically as soon as the other client (sharing the same IP
address) finished downloading. This limitation is eliminated if the
remote peer is configured with bt.allow_same_ip == TRUE.
The second limitation occurs when a client tries to download a file
located on several seeders, when those seeders share the same IP
address. This is because the clients are enforcing bt.allow_same_ip
parameter to FALSE. The client will only be able to connect to one
sender, among those having the same IP address, to download the file
(note that the client can retrieve the file from other seeders having
distinct IP addresses). This limitation is eliminated if the local
client is configured with bt.allow_same_ip == TRUE, which is somewhat
likely as those clients will directly experience better throughput by
changing their own configuration.
Mutual file sharing between hosts having the same IP address has been
checked. Indeed, machines having the same IP address can share
files with no alteration compared to current IP architectures.
5. Security Considerations
TBD
6. IANA Considerations
This document includes no request to IANA.
7. Conclusion
Despite A+P introduces some impacts on existence applications, issues
of P2P applications due to the port restricted NAT have been resolved
by UPnP extension experiment in our test bed, and other issues are
shared by other IP address sharing solutions. Therefore, from our
work, it has been proved that deploying both port range and non-
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continuous port sets A+P in the Service Provider's IPv6 network
during IPv6 transition period is feasible.
8. References
8.1. Normative References
[Implementing A+P]
Xiaoyu ZHAO.,"Implementing Public IPv4 Sharing in IPv6
Environment", ICCGI 2010
[UPnP Extension]
Xiaoyu ZHAO., "UPnP Extensions for Public IPv4 Sharing in
IPv6 Environment", ICNS 2010
8.2. Informative References
[RFC6346]
R. Bush., " The Address plus Port (A+P) Approach to the
IPv4 Address Shortage", August,2011.
[draft-boucadair-dhcpv6-shared-address-option]
M. Boucadair., "Dynamic Host Configuration Protocol (DHCPv6)
Options for Shared IP Addresses Solutions", draft-
boucadair-dhcpv6-shared-address-option-01 (work in
progress), December 21, 2009
[draft-boucadair-port-range-01]
"IPv4 Connectivity Access in the Context of IPv4 Address
Exhaustion", draft-boucadair-port-range-01(work in
progress), January 30, 2009
[Emule]
http://www.emule-project.net/. [Accessed October 26, 2009]
[UPnP SDK 1.0.4 for Linux]
http://upnp.sourceforge.net/. [Accessed October 26, 2009].
[Linux UPnP IGD 0.92].
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http://linuxigd.sourceforge.net/. [Accessed October 26,
2009].
[draft-boucadair-behave-bittorrent-portrange]
M. Boucadair.,"Behaviour of BitTorrent service in an IP
Shared Address Environment", draft-boucadair-behave-
bittorrent-portrange-02.txt
9. Additional Authors
Lan Wang
France Telecom
Hai dian district, 100190, Beijing, China
Email: lan.wang@orange-ftgroup.com
Tao Zheng
France Telecom
Hai dian district, 100190, Beijing, China
Email: tao.zheng@orange-ftgroup.com
Yan MA
Beijing University of Post and Telecommunication
Email: mayan@bupt.edu.cn
10. Acknowledgments
The experiments and tests described in this document have been
explored, developed and implemented with help from Zhao Xiaoyu, Eric
Burgey and JACQUENET Christian.
Appreciation to Randy Bush's intitial idea of documenting these
experience results, for share the knowledge of what we have learnt
with the community.
Thanks to Jan Zorz for comments.
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11. Authors' Addresses
Xiaohong Deng
France Telecom
Hai dian district, 100190, Beijing,
China
Email: dxhbupt@gmail.com
Mohamed BOUCADAIR
France Telecom
Rennes,35000 France
Email: mohamed.boucadair@orange-ftgroup.com
Yiu L. Lee
Comcast
One Comcast Center
Philadelphia, PA 19103
U.S.A.
Email: Yiu_Lee@Cable.Comcast.com
Xiaohong Huang
Beijing University of Post and Telecommunication
Email: huangxh@bupt.edu.cn
Qin Zhao
Beijing University of Post and Telecommunication
Email: zhaoqin.bupt@gmail.com
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