Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
~ wo 96109726 2 2 0 ~ 2 9 8 P~
NETWORK MAN~GEII~T FOR MULTIPLE NElWORKS
This invention relates to the management of digital
networks, and more particularly to a multi-network
architecture.
5 A clear trend in networking is for network operators to
fo~m consortiums. These consortiums are created as a
mechanism to serve customers whose scope of operation is
larger than any one network operator. A prime example is
Stentor, which was created specifically to offer
lQ customers services which are Canada-wide and span the
interests of all operating companies within Canada.
Perhaps as a consequence of the fact that there are now a
large number of network operators, it has become apparent
that the ability to provide service management which
1~ spans multiple networks is a key requirement.
For example, many network providers are Bell Operating
Companies who offer network services to their customers.
These customers realize substantial savings by buying
networking services from the Bell Operating Companies
instead of building their own private networks. For
example:
1~ They do not have to spend manpower costs maint~i~ing
and servicing these networks.
2) They do not have to spend money upgrading/replacing
or repairing the physical components that make up
the network.
.
3) They do not have to worry about network planning to
ensure that there is always enough bandwidth in the
network.
As these networks grow, and the customer base using these
networks grows, the service provider is faced with the
following factors:
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1~ Services provided by the service ~roviders are larger
in scope than a single network.
2~ Many customers require global services.
3) Within the service providers' organizations, many
divisions exist that are responsi~le for parts of the
overall service offerings.
A multi-network therefore is a network composed of two or
more interconnected networks. Individual networks
typically span a geographic area. ~he interconnections or
links between the networks can include almost any
networking interface type, such as, T1 or E1 circuits.
The issue to ~e addressed is that end customers have
network end-points in more than one network. Currently, a
customer desirous of o~t~i n; ng a connection from say
Ottawa to Vancouver must contact his local network
service provider, in this case Bell ~anada, and request a
connection of desired bandwidth to a particular address
in Vancouver. Bell Canada must then route the call
through to BCtel, for example, using a Newbridge Networks
Corporation~ 46020 network manager and advise BCtel that
a call is coming in on a certain channel and is destined
for a particular customer. BCtel must then use its 46020
network manager to route the incoming call through to the
customer. There is no way for the calling customer simply
to direct a call through to the called party through a
plurality of networks, as is now done in the public
telephone network.
From customer's perspective, it would be desirable to see
the plurality of networks as a single entity from the
point of view of establishing connections as is now the
case-for users of the switched telephone network where
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they in essence see all ~f the world's telephony netw~k
as a single ~lack box.
Even if it were possible to build a single Newbridge ~'
Networks Corporation Mainstreet~ 46020 network manager
capable of handling the entire world, this would be ~~
unaccepta~le to the myriad network operators. What is : . :
required administratively is a network architecture that
allows networks to in~eroperate.
The paper OVERVI~W OF AN INTEG~ATED NETWORK MANAGEM~NT
10 ARCHIT~CTURE FOR A I~GE HETFROGENEOUS NETWORK, IEEE 1992
NETWORK OPERATIONS AND MANAG~MENT SYMPOSIUM, Session 10,
paper 3, vol. 2, 6th April 1992, Memphis, USr pages 279-
289; J.M. Veroni discloses a multi-network architecture
comprising a plurality of di~ferent digital networks with
a network management associated with each network, a
common networ~ management network, a service manager
located at each customer premises and customer agents
associated with the service managers. The customer agents
include a data~ase including management information. This
does not, however, provide a solution to the problem
outlined a~ove. An object of the invention is to provide
such a solution.
A further object of the invention i-s to provide network
services that span more than one network.
2S According to the present invention there is provided a
multi-network architecture comprising a plurality of
- different digital networks; a network manager associated
with each network; a common management network for said
different digital networks; a service manager located at
each customer premises comprising an interface responsive
to customer input, said service manager issuing
instructions to request a desired service across the
plurality of networksi a customer agent associated with
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- each ser~ice manager and connected to the co~mon ~~
management network, each said customer agent including a ~ . .
~ . .
database cont~in;ng data about the parts of the networks ..
accessible to its associated cus~omer, and based on said
data and instructions received from its service manager,
said customer agent issuing routing instructions for the ~
required networks over said common management network; '~--
and a call processing unit associated.with the network
manager of each network, each said cali processing unit - .~
being connec~ed to the common management network and
receiving routing instructions from a said customer agent
via said management network; where~y said customer agents
can directly route a call through the plurality of
networks
The inven~ion also provides a method of managing calls
over multiple networks, each associated with a network
manager, comprising the steps of assigning a service
manager and customer agent to each customer, said service
manager providing a customer interface to permit said
customer to request a desired service and said customer
agent including a database containing data about the
networks accessible to the customer, connecting the
customer agents to a common management network spanning
said multiple networks, connecting the network managers
of said multiple networks to said common management
network by means of respective call processing units, and
establishing a call through said multiple networks by
means of instructions issued over said common management
network to said call processing units associated with the
network managers thereof.
The invention will now be described in more detail, by
way of example only, with reference to the accompanying
drawings, in which:
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Figure 1 shows a prior art multi-network system; '',
Figure 2 shows a multi-network system incorporating t ~
multi-network service managers in accordance with the
invention;
Figure 3 shows the multi-network system in more detail;
L ~ --
Figure 4 illustrates the flow of information from a , ~L--
network manager to a customer agenti ahd 5
Figure 5 shows the creation of a path in a multi-network.
~eferring to Figure 1, there exists a customer which has
access to circuits 1 in two or more separate networks 2.
This customer would like a single inter~ace to manage its
circuits. Managing these circuits includes the
connection of these circuits 1 (i.e the customer may
want to connect circuit 111-1000 and 333-3000~, and
obtaining statistics on the per~ormance and availability
o~ the network supplying the services
The,pro~lem today is that there does not exist any way
for these customers to do this, For example, i~ a
customer wishes to connect two circuits that reside in
separate networks, he or she must contact each of the
network vendors of the circuits and request services from
- each of them. If anything happened to the circuit, the
customer would not know in which network the problem
exists.
In accordance with the invention, the novel network
architecture allows service providers to provide network
services that span more than one network.
Figure 2 shows the major components that make up a Multi-
Network service manager.
In Figure 2, a service manager 4 (F) is located at each
customer premises 10. The service manager 4 includes an
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inter~ace through which the customer can access all his '',
network services which come from multiple networks. The -
~
customer need not be aware that there are multiple .
networks that make up these network services.
Each customer has a c~stomer agent 5 (D) assigned to him. .~.There is one customer agent S for each customer
regardless of the underlying networks that the-customer
has end-points in. The customer agent 5 includes a ,~
data~ase 12 cont~;n;ng information concerning the Network ~
Identifiers ~rom which elements, such as circuit,
actually reside. This information can help the customer
agent S correlate events from various networks It also
stores the ~164 addresses of the circuits. The customer
agent 5 com~lnicates with the service manager via SNMP
lS protocol~
The customer agents 5 communicate over a control network
11 that is common to all the di~ferent networks 2 for the
purpose of exchanging control informa~ion.
Each network 2 is associated with its own network manager
6, for example a Newbridge Networks Corporation
Mainstreet~ 46020, which is responsible ~or controlling
the network. The network manager 6 partitions the network
into virtual service networks (VSN). A speci~ic VSN
contains those circuit endpoints which are assigned to a
customer ~or that particular network. Each network
manager 6 is connected to a call processing unit 7
connected to the common control network 11.
The Newbridge network managers 6 supply the customer
agents 5 over the control network 11 with the information
3~ necessary for them to implement the supported MIBs and
standard extensions to those MIBs. The protocol between
the customer agents ~ and the network managers 6 can be a
standard protocol, such as CMIP, SNMP, etc
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The call processing units 7 (B~ are responsible for the
routing of PVCs ~Permanent Virtual Connec~ions) over the
Inter-network links 8, i.e. they select a link ~etween ~-
two networ~s for a PVC to ride on and issue appropriate
5 instructions to the network manager 6. The protocol to
used for this component is SS7. ~'~
Each network management system 6 is configured such that
there is a customer agent associated with each VSN The ,~,
network management system sends configuration, state and
performance (statistical~, and fault data regarding the
circuit end-points in a VSN to the associated customer
agent In this way a customer agent can consolidate this
information ~rom a number of net~ork manage~ent systems
in order to maintain information about all customer
circuit end-points regardless of which network they are
located in. The network management systems notify the
customer agents of any changes to such information
immediately Figure 4 illustrates the ~low of information
from a network manager 6, such as the 46020, to a
customer agent 5.
Figure 5 illustrates how an end customer can create,
delete and monitor paths between aircuit end-points
Firstr a service manager 4 at a customer premise requests
a list of idle circuit end-points from its associated
customer agent 5 The service manager ~ selects the two
available circuit endpoints (source and destinati-on) that
are to he interconnected and sends a "Create Path"
request to the customer agent 5 speci~ying the circuit
end-points by their network address ~E. 164~ or
equivalent) and any path related parameters such as the
data speed.
The customer agent 5 then validates the request and
translates the source and destination circuit addresses
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into which physical network devices these addresses - ,.
represent it, and forwards the request to the call
processing unit 7 associated with the source network 2. ',~ t
The source call processing unit 7 determines which inter-
network traffic Link 8 should be used to create a path to '~
the destination network.
Having determined which traffic link to use, the source
call processing unit selects which bandwidth on the link - .
8 is to ~e used. It then instructs the associate network
manager to connect the source circuit end-point to the
inter-network traffic link 8.
The source call p~ocessing component then sends a create
path request to the call processing unit associated with
the destination network giving the source as inter-
network tra~fic lin~ 8 and the destination as theoriginally specified customer circuit end-point.
Finally, the destination call processing component
instructs its associated network manager to make the
connection from 8 to the destination end-point. At that
point, the circuit is complete.
To take an example, supposing cus~omer ABC has been
allocated circuits from 3 separate networks. The
allocation of the circuits is carried out from the VSN
partitioning system provided in network manager 6. This
system allows the definition of the customer (i e. the
VSN name) and the allocation of circuits to that customer
(i.e add a circuit~to~a VSN partit-ion)
The customer, via a service management agent 8, now has
the capability to request service from the customer agent
5 (i.e request that two circuits be connected3 The
customer agent can now request the call process unit 7 to
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connect the two circuits over the common control network ,',
1 1 . ~, .
The call processing system attempts to route the call,
requesting physical connections from various 46020s (i.e. .
S different networks) to pro~ide data ~low between the .
circuits.
In order to better understand the inventionj network
operations in this context can be viewed as being
composed of two distinct components. First, the physical
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equipment and links must be installed and placed into and
active state. This is called network management. The
second major component is that of service provisioning
where that equipment is assigned or allocated to
providing a particular end user service.
Traditionally, it has been possible to assume that the
responsi~ility for equipment and service provisioning -
were in ~act the same organization. For example, the
New~ridge Networks Corporation 46020 interfaces reflect
this view in that both functions are closely linked.
However, in the multi-network situation, this is not
true. Each network operator is clearly responsible for
the equipment and facilities that they have pro~ided.
Service provisioning is done by the end-user or may be
provided by one of the network operators. The linkage
between the e~uipment management functions and the
service provisioning functions must be broken in order to
deal with this situation.
Several examples will now be considered.
In a first example, two or more network operators have
formed a consortium. Inter-network links are provided
between the networks. End-customers have terminations in
one or more of the networks.
Each customer uses one of the network operators as their
administrative or prime contact. ~equests for service
changes all ~o to that operator. The operator looks after
any arrangements with the other operators such as
equipment/facility installation and will establish the
connections.
Customer connections can span networks and can tandem
through a network as needed.
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Each network operator wishes to allocate bandwidth in
their network to the consortium. They will ~or instance
want to control the amount of bandwidth of their overall
network allocated to tandem traffic.
Some examples o~ these consortiums are Stentor, FNA and
NYN~X (NY Tel and NE Tel).
In a second example, a network operator is a member of
several consortiums. In the US, an RBOC might form
consortiums with several different interexchange carriers
(IXCs) and other RBOCs. A given customer could have
t~rmin~tions in different consortiums. ~urther the
customer prime has an opportunity to do least cost
routing over the IXC networks in order to min;mi ~e their
costs. This may also come about where dif~erent
consortiums may be formed to offer different services
(TDM, Frame Relay, ATM, etc.~.
In a third example, a multi-network includes both public
and private networks. In this scenario, a customer has
its own private Newbridge network. The customer wants to
make use of a public network such as Enterprise to
interconnect sites using the 'lon demand" capabilities for
establishing ~andwidth in near real-time.
A fourth example is the reverse of the above example,
where a customer wishes to_ utsource management of their
network to a public network operator.
Each Qf the individual networks is managed by a network
- - operator. This is called "network management". Network
management is concerned with physical hardware components
and their interconnections ~links). A given network
manager has no visibility into other networks. They are
aware of the inter-network links though only as network
.
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end-points. The ~unctions perfonmed by a network manager
are: ~
Within a network, it is expected that the network manager
can cause connections between end-points to ~e created.
I~ a fault occurs within a network, then that fault must
.. ,,~
be detected and where possible must ~e corrected by
rerouting.
The network must be monitored at periodic intervals for
traffic and fault information
End users must have a mechanism for requesting
connections from the set of networks that they have
access to. This mechanism is called call service
management. A user requests that two generic addresses
(E.164 or equivalent) be connected. Service management
must validate that the connection request makes sense,
that the end-points are compatible and that the user has
permission to make the connection. The user may have the
ability to con~igure the connection end-points.
A key requirement of the multi-networking scheme is that
there be a way to uniquely identify network endpoints
that is not network or worse e~uipment based. It is not
reasona~le to expect all networks to understand the
addressing quirks of all other networks. As a result, a
common network independent addressing scheme is needed.
The E.164 addresses are a very reasona~le instance of
such a scheme.
User requests for connections are expressed in terms o~
these addresses.
Each network has an associated network management
component which is effectively a 4602 with additional
applications. Network management components are linked
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together using TCP/IP over the common control network 11,
as shown in Figure 3. ..
While a customer may span multiple network provider ' ,''
networks, the service provider will allocate network '~
endpoints to a particular customer. The network provider ,;,.
must create a "closed user group" for each customer that ~....'
they are dealing with. This is absolutely necessary as a
security issue. The 4602 provides a very convenient w~y
to accomplish this through Virtual Service Networks
(VS~ A VSN partition will be created for each customer
that the network operator is dealing with. All endpoints '
which are to ~e allocated to that customer will ~e placed
into that VSN~
A customer may now have VSNs created for them in multiple
networks.
Internetwork traffic links are NOT generally part of a
customer VSN. They will be allocated to a customer at
service provisioning time.
The call processing unit 7 provides the intelligence for
linking the various networks. There will be one such
instance per 46020 and it is expected to run on the same
hardware platform. It has knowledge of the other network
call processing entities in the network. ~t also has
knowledge of the inter-network links.
2~ When a connection is initiated, the call processing (CP)
unit 7 uses its routing tables to select a route which is
- - a set of Internetwork links and of course the two - -
connection endpoints. It causes those connections to be
setup by commllnicating with the call processing unit for
those networks. A connection across a particular network
will be accomplished by the call processing agent by
having it create a call with the appropriate parameters
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- in the network manager (4602) and then connecting the ~
call. ~. ~
The interface between call processing modules must be ' ' '
well defined. It may, for example, be a variant on Q.931 ''
5 or SS7. This allows a degree of openness to the ,
architecture such that other equipment and management ~.,.,~
architectures could be used to provide transport
~unctions ~SON~T, ~ACS, etc.~.
A customer will be have one and only one customer agent.
That agent will acquire knowledge of the endpoints that
make up that customer's domain from the individual ~ ' -
networked 46020s. The only information that is retained
is the address of the endpoints When the customer is
created or under error conditions, the agent will refresh
1~ that view from the network managers 6 using queries on
the various 46020 databases. By using the change
noti~ier, it can then track additions~deletions from the
set of customer endpoints as a result of network operator
actions.
It must also retain knowledge of the multi-network
connectivity that a customer has requested. Port to port
connections are created through use of a network call
processing unit.
~lthough, in Figure 2 the customer agents ~ are shown as
separate from the 4602/CP and from each other They can
of course ~e deployed in any number of physical platforms
as needed.
The interface from the customer agent to the network
manager 6 can be a client~server database interface
(SQL) This does mean that the customer end-points for a
customer network must be managed by a network manager
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This is a tool for the service user. This function may
however ke provided by the service provider. A user is ~. '
presented a VSN type view o~ their network composed of
all of the ports that have been assigned to them. They
may configure p~rt parameters and may connect ports. The
....
service user need not be aware of which network the ports
....
physically reside in. .
The user inte~ace also allows the end-user to organize
the ports into groups like folders on a Mac so that the
user can impart some order to their network. There are a
variety-of methods that might be used to build this
product, but using a "standard'- network manager such as
HP OpenView would probably be a very attractive option.
All commlln;cation from this unit is to the customer agent
associated with the customer. A given c~stomer agent can
support multiple CSMs.
It is also necessary that a single platform be able to
support multiple instances o~ the service manager ~or the
situation where a network operator is providing the
service management of a num~er of customers from a single
station.
The interface to the customer agent can be either a
~r~prietary interface ~ased around remote SQL RPCs or can
be via SNMP with a Newbridge MIB such that a standard
SNMP manager can get infonmation from the agent.
A single network is currently limited in size by the
capacity of a single 4602 network manager and other
related issues such as CPSS networking limits. There are
a number of programs underway to address all of these
limits with the intent that a single network can be grown
to whatever size is needed.
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However, there are a number of significant technical
challenges in doing this. The architecture described ~ ~. ~
above is capable of solving a subset of the very large . ~ ,
network problem. A single network ope~ator can sub-divide
their network into interconnected regional networks. The
, ~ . .
customer agent and customer service manager can then
provide the end-to-end service model. ..
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E.~Drr~~ S~'
