U.S. patent application number 15/367511 was filed with the patent office on 2018-06-07 for selective mac address learning.
The applicant listed for this patent is Adtran, Inc.. Invention is credited to Chad Anthony Dieselberg, Nagaraj Padur.
Application Number | 20180159772 15/367511 |
Document ID | / |
Family ID | 62234876 |
Filed Date | 2018-06-07 |
United States Patent
Application |
20180159772 |
Kind Code |
A1 |
Dieselberg; Chad Anthony ;
et al. |
June 7, 2018 |
SELECTIVE MAC ADDRESS LEARNING
Abstract
Methods, systems, and apparatus for selective MAC address
learning are disclosed. In one aspect, multiple different packets
are received by a telecommunications device. The multiple different
packets include different source MAC addresses. For each of the
multiple different packets, a distribution type is determined. The
distribution type is one of a one-to-one distribution type or a
one-to-many distribution type. Based on the determined distribution
type of the particular packet, a forwarding table of the
telecommunications device is selectively updated. When the
particular packet has the one-to-many distribution type, a source
MAC address that is included in the particular packet is not stored
in the forwarding table. When the particular packet has the
one-to-one distribution type, the source MAC address that is
included in the particular packet is stored in the forwarding
table.
Inventors: |
Dieselberg; Chad Anthony;
(Madison, AL) ; Padur; Nagaraj; (Madison,
AL) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Adtran, Inc. |
Huntsville |
AL |
US |
|
|
Family ID: |
62234876 |
Appl. No.: |
15/367511 |
Filed: |
December 2, 2016 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H04L 45/7457 20130101;
H04L 45/16 20130101; H04B 10/27 20130101; H04L 45/02 20130101; H04L
45/66 20130101; H04L 61/6022 20130101 |
International
Class: |
H04L 12/743 20060101
H04L012/743; H04L 12/751 20060101 H04L012/751; H04L 12/721 20060101
H04L012/721; H04L 12/761 20060101 H04L012/761; H04B 10/27 20060101
H04B010/27; H04L 29/12 20060101 H04L029/12 |
Claims
1. A method comprising: receiving, by a telecommunications device,
multiple different packets that include different source MAC
addresses; determining a distribution type of each of the multiple
different packets, wherein the distribution type is one of a
one-to-one distribution type or a one-to-many distribution type,
and determined based on a destination address that is specified in
each of the multiple different packets; and selectively updating a
forwarding table of the telecommunications device based on the
determined distribution type of each particular packet, including:
not storing a source MAC address that specifies a source of the
particular packet when the particular packet has the one-to-many
distribution type; and storing the source MAC address that
specifies the source of the particular packet when the particular
packet has (i) the one-to-one distribution type and (ii) the
destination address specifying that the telecommunications device
is a destination of the particular packet.
2. The method of claim 1, wherein receiving the multiple different
packets comprises receiving the multiple different packets that are
transmitted over a same V-LAN.
3. The method of claim 1, wherein the telecommunications device is
an Optical Network Unit (ONU).
4. The method of claim 1, wherein the telecommunications device is
an Optical Line Termination (OLT).
5. The method of claim 1, wherein determining the distribution type
of each of the multiple different packets includes: identifying
unicast packets that have known destination MAC addresses; and
determining that the unicast packets are of the one-to-one
distribution type.
6. The method of claim 1, wherein packets of the one-to-many
distribution type include broadcast packets and multicast
packets.
7. The method of claim 1, wherein the forwarding table of the
telecommunications device is a Content Addressable Memory (CAM)
forwarding table.
8. A telecommunications device, comprising: a communications
interface that communicatively couples the telecommunications
device with a plurality of network devices; a memory structure
storing machine executable instructions; and one or more processors
that execute the machine executable instructions and perform
operations including: receiving multiple different packets that
include different source MAC addresses; determining a distribution
type of each of the multiple different packets, wherein the
distribution type is one of a one-to-one distribution type or a
one-to-many distribution type, and determined based on a
destination address that is specified in each of the multiple
different packets; and selectively updating a forwarding table of
the telecommunications device based on the determined distribution
type of each particular packet, including: not storing a source MAC
address that specifies a source of the particular packet when the
particular packet has the one-to-many distribution type; and
storing the source MAC address that specifies the source of the
particular packet when the particular packet has (i) the one-to-one
distribution type and (ii) the destination address specifying that
the telecommunications device is a destination of the particular
packet.
9. The device of claim 8, wherein receiving the multiple different
packets comprises receiving the multiple different packets that are
transmitted over a same V-LAN.
10. The device of claim 8, wherein the telecommunications device is
an Optical Network Unit (ONU).
11. The device of claim 8, wherein the telecommunications device is
an Optical Line Termination (OLT).
12. The device of claim 8, wherein determining the distribution
type of each of the multiple different packets includes:
identifying unicast packets that have known destination MAC
addresses; and determining that the unicast packets are of the
one-to-one distribution type.
13. The device of claim 8, wherein packets of the one-to-many
distribution type include broadcast packets and multicast
packets.
14. The device of claim 8, wherein the forwarding table of the
telecommunications device is a Content Addressable Memory (CAM)
forwarding table.
15. A system, comprising: a plurality of network devices, each
network device configured to send packets to a telecommunications
device; and the telecommunications device configured to: receive
multiple different packets that include different source MAC
addresses; determine a distribution type of each of the multiple
different packets, wherein the distribution type is one of a
one-to-one distribution type or a one-to-many distribution type,
and determined based on a destination address that is specified in
each of the multiple different packets; and selectively update a
forwarding table of the telecommunications device based on the
determined distribution type of each particular packet, including:
not storing a source MAC address that specifies a source of the
particular packet when the particular packet has the one-to-many
distribution type; and storing the source MAC address that
specifies the source of the particular packet when the particular
packet has (i) the one-to-one distribution type and (ii) the
destination address specifying that the telecommunications device
is a destination of the particular packet.
16. The system of claim 15, wherein receiving the multiple
different packets comprises receiving the multiple different
packets that are transmitted over a same V-LAN.
17. The system of claim 15, wherein the telecommunications device
is an Optical Network Unit (ONU).
18. The system of claim 15, wherein the telecommunications device
is an Optical Line Termination (OLT).
19. The system of claim 15, wherein determining the distribution
type of each of the multiple different packets includes:
identifying unicast packets that have known destination MAC
addresses; and determining that the unicast packets are of the
one-to-one distribution type.
20. The system of claim 15, wherein packets of the one-to-many
distribution type include broadcast packets and multicast packets.
Description
BACKGROUND
[0001] This specification relates to MAC address learning.
[0002] Ethernet switching devices generally learn MAC addresses
using a Source-Address-Learning method. For each received Ethernet
packet, an Ethernet switching device learns MAC address of packet
source via source MAC address in the Ethernet packet. The Ethernet
switching device can store the learned source MAC address in its
Content Addressable Memory (CAM) forwarding table.
SUMMARY
[0003] In general, one innovative aspect of the subject matter
described in this specification can be embodied in methods for
selective MAC address learning by network devices with limited MAC
address Content Addressable Memory (CAM) forwarding table spaces in
Ethernet MAC-Switched Networks. One example computer-implemented
method includes receiving, by a telecommunications device, multiple
different packets that include different source MAC addresses,
determining a distribution type of each of the multiple different
packets, the distribution type being one of a one-to-one
distribution type or a one-to-many distribution type, and
selectively updating a forwarding table of the telecommunications
device based on the determined distribution type of the particular
packet. The selectively updating comprises the following
operations: not storing a source MAC address that is included in
the particular packet when the particular packet has the
one-to-many distribution type, and storing the source MAC address
that is included in the particular packet when the particular
packet has the one-to-one distribution type.
[0004] These and other embodiments can each, optionally, include
one or more of the following features. Receiving the multiple
different packets comprises receiving the multiple different
packets that are transmitted over a same Virtual LAN (V-LAN). The
telecommunications device is an Optical Network Unit (ONU). The
telecommunications device is an Optical Line Termination (OLT).
Determining the distribution type of each of the multiple different
packets comprises the following operations: identifying unicast
packets that have known destination MAC addresses, and determining
that the unicast packets are of the one-to-one distribution type.
Packets of the one-to-many distribution type include broadcast
packets and multicast packets. The forwarding table of the
telecommunications device is a Content Addressable Memory (CAM)
forwarding table.
[0005] Particular embodiments of the subject matter described in
this specification can be implemented so as to realize one or more
of the following advantages. The methods, devices, and/or systems
described in the present disclosure can selectively learn MAC
addresses, by a telecommunications device, using a
Source-Address-Learning method based on a distribution type of each
received packet. If the received packet is a unicast packet, source
MAC address in the received packet can be learned (e.g., used to
update a CAM forwarding table of the telecommunications device).
However, if the received packet is a broadcast packet or a
multicast packet, the source MAC address in the received packet
will not be learned (e.g., not used to update the CAM forwarding
table of the telecommunications device). In doing so, MAC addresses
that typically do not carry traffic for the telecommunications
device (i.e., undesirable MAC addresses) will not be stored in the
CAM forwarding table of the telecommunications device, thereby
resulting in more efficient use of a limited amount of memory
available in the telecommunications device. For example, in
situations where the telecommunications device has a limited CAM
forwarding table space, desirable MAC addresses (i.e., MAC
addresses that carry traffic specifically addressed for delivery to
the telecommunications device) stored in the CAM forwarding table
will not be over-written by undesirable MAC addresses that
typically do not carry traffic for the telecommunications device
(e.g., source MAC addresses in broadcast/multicast packets that are
note specifically addressed for delivery to the telecommunications
device). In addition, since the CAM forwarding table stores only
desirable MAC addresses, the likelihood of flooding a unicast
packet due to unknown destination MAC address in the CAM forwarding
table will be reduced. As a result, allocated bandwidth of an
Ethernet LAN (E-LAN) can be preserved from being flooded (e.g.,
used up) with unicast packets, thereby making the allocated
bandwidth available to carry assigned traffic, especially on E-LANs
with many hosts that generate significant broadcast/multicast
traffic.
[0006] While some aspects of this disclosure refer to
computer-implemented software embodied on tangible media that
processes and transforms data, some or all of the aspects may be
computer-implemented methods or further included in respective
systems or devices for performing the described functionality. The
details of one or more embodiments of the subject matter described
in this specification are set forth in the accompanying drawings
and the description below. Other features, aspects, and advantages
of the subject matter will become apparent from the description,
the drawings, and the claims.
DESCRIPTION OF DRAWINGS
[0007] FIG. 1 is a block diagram illustrating an example networking
environment for selective MAC address learning.
[0008] FIG. 2 is a block diagram illustrating an example networking
environment for an example telecommunications device to selectively
update its Content Addressable Memory (CAM) forwarding table.
[0009] FIG. 3 is a flow chart of an example process for selectively
learning MAC addresses based on received packet distribution
types.
[0010] Like reference numbers and designations in the various
drawings indicate like elements.
DETAILED DESCRIPTION
[0011] This document describes methods, systems, and apparatus for
selective MAC address learning that is performed by a
telecommunications device (e.g., an Optical Network Unit (ONU)).
For example, a telecommunications device can use a
Source-Address-Learning method to learn MAC addresses (e.g., store
the MAC addresses in a forwarding table of the telecommunications
device) only from unicast packets, rather than storing MAC
addresses for all communications packets. For example, MAC
addresses in broadcast and/or multicast packets are not learned
and/or stored in the forwarding table of the telecommunications
device. Although this disclosure refers to optical
telecommunications systems for purposes of example, the subject
matter of this document can be applied to other types of
telecommunications systems or other systems that offer Ethernet LAN
(E-LAN) service.
[0012] An Ethernet MAC-switched network can connect a large number
of hosts (e.g., computers, Optical Network Terminals, business
CPEs, xDSL modems, cable modems, residential gateways). When using
a Source-Address-Learning method, each switching device in the
Ethernet MAC-switched network can learn MAC addresses of the hosts
via source MAC addresses in received packets, and may require a
large Content Addressable Memory (CAM) forwarding table to learn
(i.e., store) addresses of the large number of hosts. When a CAM
forwarding table in a switching device (e.g., an inexpensive
switching device) is limited in size, the addresses of the large
number of hosts cannot all be learned, and most of the addresses
may remain unknown to the switching device. In addition, due to
various protocols (e.g., ARP, ICMPv6) that use broadcast and/or
multicast packets which are flooded, the CAM forwarding table may
be routinely over-written with MAC addresses learned from source
MAC addresses of broadcast and/or multicast packets from hosts for
which the switching device typically does not carry traffic (e.g.,
undesirable MAC addresses). Furthermore, Ethernet packets with
unknown destination MAC addresses (e.g., destination MAC address
not found in the CAM forwarding table) are flooded (e.g.,
transmitted over all ports). When there is a constant background
broadcast and/or multicast traffic in the network, the switching
device may be continuously over-writing its CAM forward table with
MAC addresses that typically do not carry traffic for the switching
device (e.g., undesirable MAC addresses), and thereby flooding most
(if not nearly all) traffic. Flooding unicast packets (e.g.,
transmitted unicast packets over all ports) may reduce network
capacity and affect allocated bandwidth in large-scale MAC-switched
networks.
[0013] The disclosed subject matter addresses problems that arise
when carrier Ethernet E-LAN service (i.e., MAC-switched service) is
offered via a Passive Optical Network (PON) (e.g., a Gigabit
Passive Optical Network (GPON)) and/or Optical Network Units (ONUs)
(also referred to as Optical Network Terminals (ONTs)) at the
network edge have limited CAM space. In the present disclosure,
instead of learning all MAC addresses in received packets, a
telecommunications device (e.g., a switching device, an ONU, an
Optical Line Termination (OLT)) selectively learns MAC addresses in
the received packets to utilize its limited CAM forwarding table
more efficiently. In the selective learning model, the
telecommunications device learns MAC Addresses by
Source-Address-Learning and only learns source MAC addresses of
unicast packets. For example, when receiving unicast packets, the
telecommunications device learns source MAC addresses in the
received unicast packets and store (or update) the learned source
MAC addresses in its CAM forwarding table. However, when receiving
broadcast and/or multicast packets, the telecommunications device
will not learn source MAC addresses in the received broadcast
and/or multicast packets. As a result, the CAM forwarding table
will not be routinely over-written by broadcast and/or multicast
traffic. In doing so, the limited CAM space may be used to store
MAC addresses only when unicast traffic is seen from the source,
thereby improving the likelihood that MAC addresses that carry
traffic specifically addressed for delivery to the
telecommunications device are stored in its CAM forwarding table.
As a result, flooding a unicast packet due to unknown destination
MAC address in the CAM forwarding table may be reduced. In
addition, allocated bandwidth of an E-LAN can be preserved from
flooded unicast packets.
[0014] FIG. 1 is a block diagram illustrating an example networking
environment 100 for selective MAC address learning. As illustrated
in FIG. 1, the environment 100 includes an access node 102, an
E-LAN 106 that provides Ethernet service, and network 130. The
access node 102 (e.g., TA5000) can serve as a first aggregation
point to the network 130. In some implementations, the environment
100 may include additional and/or different components not shown in
the block diagram, such as one or more access nodes, another type
of network that provides network services, or a combination of
these and other technologies. In some implementations, components
may also be omitted from the environment 100. As illustrated in
FIG. 1, the E-LAN 106 is depicted as a single E-LAN, but may be
comprised of more than one E-LANs without departing from the scope
of this disclosure.
[0015] As illustrated, the access node 102 includes a switch
component 104 and an OLT 108. The switch component 104 connects the
OLT 108 to the network 130. In some implementations, the switch
component 104 forwards packets from the network 130 to the E-LAN
106 and forwards packets from the E-LAN 106 to the network 130. In
addition to the data plane forwarding functionality, the switch
component 104 is also responsible for forwarding management traffic
between the access node 102 and a management system in the
network.
[0016] As illustrated, the E-LAN 106 includes the OLT 108 at a
service provider's central office (or other distribution point) and
a number of ONUs 110, 112, and 114, which are located near end
users. The OLT 108 is coupled to the number of ONUs 110, 112, and
114, thereby forming a point-to-multipoint Passive Optical Network
(PON). For example, in the case of Gigabit Passive Optical Network
(GPON), a single OLT can have 8 (or another number of) ports and
each port can connect to 128 (or another number of) different
ONUs.
[0017] The OLT 108 learns the MAC addresses of each ONU (e.g., ONU
110, ONU 112, ONU 114) and/or the residential gateways connected to
those ONUs via source MAC addresses in received packets. Similarly,
it also learns MAC addresses of the devices connected to the switch
component upstream in the network via source MAC addresses in
received packets. In some implementations, the OLT 108 may
selectively learn MAC addresses based on received packet
distribution types (discussed in more detail below). When packets
are received from the switch component 104 and are not destined to
the OLT 108, the OLT 108 may check the packets and its CAM
forwarding table to determine how and where to forward the packets.
For example, if receiving a broadcast packet 120, the OLT 108 may
forward the broadcast packet 120 to all ONUs including ONU 110, ONU
112, and ONU 114. If receiving a unicast packet 122 to ONU 110 or
one or more devices connected to the ONU, the OLT 108 may forward
the unicast packet 122 to the ONU 110.
[0018] The ONUs (e.g., ONU 110, ONU 112, ONU 114) are generally
located at network edge and have limited CAM spaces. In normal
operations, only several MAC addresses are needed in a CAM table of
an ONU since traffic of the ONU is normally between the OLT and one
or more devices connected to the ONU. To prevent its limited CAM
table from being over-written by undesirable MAC addresses, the ONU
implements selective MAC address learning via source MAC addresses
in received packets. For example, when receiving a unicast packet
122, ONU 110 may learn the source MAC address that is included in
the received unicast packet 122, and store the learned source MAC
address in its CAM table. When receiving a broadcast packet 120 (or
a multicast packet not shown in FIG. 1), the ONU 110 will not
perform source MAC address learning on the received broadcast
packet 120. As a result, the CAM table of the ONU 110 will not be
over-written by the source MAC address included in the received
broadcast packet 120, which is generally undesirable to the ONU
110. ONU 112 and ONU 114 also receive the broadcast packet 120 sent
over the E-LAN 106. In this example, neither the ONU 112 nor the
ONU 114 will perform source MAC address learning on the received
broadcast packet 120 because the broadcast packet 120 is not a
unicast packet. As a result, CAM tables of the ONU 112 and the ONU
114 will not be over-written by the source MAC address included in
the received broadcast packet 120.
[0019] The network 130 facilitates wireless or wireline
communications between the components of the environment 100 with
any other local or remote computer, such as additional E-LANs,
servers, or other devices communicably coupled to the network 130,
including those not illustrated in FIG. 1. As illustrated in FIG.
1, the network 130 is depicted as a single network, but may be
comprised of more than one network without departing from the scope
of this disclosure.
[0020] In some situations, one or more of the illustrated
components may be implemented, for example, as one or more
cloud-based services or operations. The network 130 may be all or a
portion of a service provider's access or aggregation network, an
enterprise or secured network, or at least a portion of the network
130 may represent a connection to the Internet, a public switched
telephone network (PSTN), a data server, a video server, or
additional or different networks. In some implementations, a
portion of the network 130 may be a virtual private network (VPN).
Further, all or a portion of the network 130 can comprise either a
wireline or wireless link. Example wireless links may include
802.11ac/ad/af/a/b/g/n, 802.20, WiMax, LTE, and/or any other
appropriate wireless link. In other words, the network 130
encompasses any internal or external network, networks,
sub-network, or combination thereof, operable to facilitate
communications between various computing components, inside and
outside the environment 100. The network 130 may communicate, for
example, Internet Protocol (IP) packets, Frame Relay frames,
Asynchronous Transfer Mode (ATM) cells, voice, video, data, and
other suitable information between network addresses. The network
130 may also include one or more local area networks (LANs), radio
access networks (RANs), metropolitan area networks (MANs), wide
area networks (WANs), all or a portion of the Internet, and/or any
other communication system or systems at one or more locations.
[0021] FIG. 2 is a block diagram illustrating an example networking
environment 200 for an example telecommunications device (i.e., ONU
110) to selectively update its Content Addressable Memory (CAM)
forwarding table. The environment 200 shown in FIG. 2 illustrates a
simple interaction between the OLT 108 and the ONU 110 when the OLT
108 forwards (or transmits) a broadcast packet 120 and a unicast
packet 122 to the ONU 110. In some implementations, the environment
200 may include additional and/or different components not shown in
the block diagram. Components may also be omitted from the
environment 200. The components illustrated in FIG. 2 may be
similar to or different from those described in FIG. 1.
[0022] As illustrated in FIG. 2, the environment 200 includes the
OLT 108 and the ONU 110. The ONU 110 includes a receiver optical
sub-assembly (ROSA) 202 for receiving downstream data from the OLT
108, a processor 204, a CAM table 206, and a trash can 208 (e.g., a
place to hold received broadcast and multicast packets). In
operation, the ROSA 202 receives an optical signal as input, and
outputs an electric signal.
[0023] As illustrated in FIG. 2, the ONU 110 includes a processor
204. Although illustrated as a single processor 204 in FIG. 2, two
or more processors may be used according to particular needs,
desires, or particular implementations of the ONU 110. Each
processor 204 may be a central processing unit (CPU), an
application-specific integrated circuit (ASIC), a
field-programmable gate array (FPGA), or another suitable
component. Generally, the processor 204 executes instructions and
manipulates data to perform the operations of the ONU 110.
Specifically, the processor 204 executes the selective source MAC
address learning described in the illustrated figures, including
the operations performing the functionality associated with the ONU
110. For example, the processor 204 can determine whether a
received packet is a unicast packet, broadcast packet, or a
multicast packet based on, for example, an identified destination
IP address in the received packet. In addition, the processor 204
can determine the source MAC address included in the received
packet (e.g., identify the source MAC address at some specific
location of the received packet).
[0024] For purposes of example, assume that a broadcast packet 120
is received from the OLT 108, and that the processor 204 determines
that the received packet is a broadcast packet (e.g., a packet
having a one-to-many distribution type) based on, for example, a
broadcast MAC/IP address identified in the broadcast packet 120. In
this example, the processor 204 will not perform source MAC address
learning for the broadcast packet 120 because the packet is a
broadcast packet. After processing the broadcast packet 120 (e.g.,
obtaining data in the payload area), the broadcast packet 120 is
dropped, for example, in the trash can 208.
[0025] In another example, assume that a unicast packet 122 is
received from the OLT 108, and that the processor 204 determines
that the received packet is a unicast packet (e.g., a packet having
a one-to-one distribution type) based on, for example, a unicast
MAC or IP address identified in the unicast packet 122. In this
example, the processor 204 will perform source MAC address learning
for the unicast packet 122 because the packet is a unicast packet
rather than a broadcast or multicast packet. For example, the
processor 204 identifies the source MAC address in the unicast
packet 122, and stores the source MAC address in the CAM table 206
if the source MAC address has not been previously (e.g., is not
currently) stored in the CAM table 206. In some implementations, if
the source MAC address is already in the CAM table 206, no action
is required to update the table.
[0026] FIG. 3 is a flow chart of an example process 300 for
selectively learning MAC addresses based on received packet
distribution types. The example process 300 can be performed, for
example, by one or more telecommunications devices, such as those
described with reference to FIGS. 1 and 2 (e.g., OLT 108, ONU 110).
The example process 300 can also be implemented as instructions
stored on a non-transitory, computer-readable medium that, when
executed by one or more telecommunications devices, configures the
one or more telecommunications devices to perform and/or cause the
one or more telecommunications devices to perform the actions of
the example process 300.
[0027] Multiple different packets are received by a
telecommunications device (305). The multiple different packets
include different source MAC addresses. In some implementations,
the multiple different packets are transmitted over a same Virtual
LAN (V-LAN) and received by the telecommunications device over the
V-LAN. In some implementations, the packets are Ethernet packets.
The telecommunications device can be an Optical Network Unit (ONU)
or an Optical Line Termination (OLT) in a Gigabit Passive Optical
Network (GPON) offering carrier Ethernet LAN (E-LAN) service. This
implementation equally applies to more advanced recent 10G PONs as
well and not limited to GPON. E-LAN is a special form of V-LAN
(i.e., a point to multipoint V-LAN) and the E-LAN service is
MAC-switched.
[0028] For each of the multiple different packets, a distribution
type is determined (310). The distribution type is one of a
one-to-one distribution type or a one-to-many distribution type.
For example, a unicast packet has a distribution type of
one-to-one. A broadcast packet or a multicast packet has a
distribution type of one-to-many. In some implementations, a
unicast packet with an unknown destination MAC address may be
flooded. In some implementations, the flooded unicast packet still
has a distribution type of one-to-one.
[0029] A determination is made whether the distribution type of the
particular packet is one-to-one or one-to-many (315). If the
particular packet has the one-to-one distribution type (e.g., a
unicast packet), a forwarding table of the telecommunications
device is updated (320). For example, a source MAC address that is
included in the particular packet is stored in the forwarding
table, for example, if not previously stored (e.g., if not
currently found in the forwarding table).
[0030] A unicast packet with an unknown destination MAC address
will be flooded on an E-LAN since the destination MAC address is
unknown. In such situation, if the telecommunications device is the
destination of the unicast packet, the telecommunications device
will update its forwarding table with the source MAC address that
is included in the unicast packet. If the telecommunications device
is not the destination of the unicast packet, the
telecommunications device will not update its forwarding table with
the source MAC address that is included in the unicast packet. In
some implementations, the forwarding table of the
telecommunications device is a Content Addressable Memory (CAM)
forwarding table.
[0031] If the particular packet has the one-to-many distribution
type (e.g., a broadcast packet or a multicast packet), the
forwarding table of the telecommunications device is not updated
(325). For example, the source MAC address that is included in a
broadcast packet or a multicast packet will not be stored in the
forwarding table of the telecommunications device even when the
source MAC address has not been previously stored in the forwarding
table (e.g., is not currently found in the forwarding table). In
some implementations, the telecommunications device only learns
source MAC addresses of unicast packets (e.g., only updates its
forwarding table with the source MAC addresses that are included in
the unicast packets).
[0032] The example process 300 shown in FIG. 3 can be modified or
reconfigured to include additional, fewer, or different actions
(not shown in FIG. 3), which can be performed in the order shown or
in a different order. For example, before 310, the
telecommunications device identifies unicast packets that have
known destination MAC addresses. In addition, the
telecommunications device determines that the unicast packets are
of the one-to-one distribution type. In some implementations, one
or more of the actions shown in FIG. 3 can be repeated or iterated,
for example, until a terminating condition is reached. In some
implementations, one or more of the individual actions shown in
FIG. 3 can be executed as multiple separate actions, or one or more
subsets of the actions shown in FIG. 3 can be combined and executed
as a single action. In some implementations, one or more of the
individual actions shown in FIG. 3 may also be omitted from the
example process 300.
[0033] While this specification contains many specific
implementation details, these should not be construed as
limitations on the scope of any inventions or of what may be
claimed, but rather as descriptions of features specific to
particular embodiments of particular inventions. Certain features
that are described in this specification, in the context of
separate embodiments, can also be implemented in combination or in
a single embodiment. Conversely, various features that are
described in the context of a single embodiment can also be
implemented in multiple embodiments, separately, or in any suitable
subcombination. Moreover, although features may be described above
as acting in certain combinations and even initially claimed as
such, one or more features from a claimed combination can, in some
cases, be excised from the combination, and the claimed combination
may be directed to a subcombination or variation of a
subcombination.
[0034] Thus, particular embodiments of the subject matter have been
described. Other embodiments are within the scope of the following
claims. In some cases, the actions recited in the claims can be
performed in a different order and still achieve desirable results.
In addition, the processes depicted in the accompanying figures do
not necessarily require the particular order shown, or sequential
order, to achieve desirable results.
* * * * *