Methods for constructing PNNI networks with optimized architecture
AssigneeAT&T Corp.
InventorEric Rosenberg
Life of this patent
Estimating the term…
Abstract
The specification describes techniques for evaluating important network performance parameters, for example, call set-up time, for private network-to-network (PNNI) interfaces. These performance parameters are used to determine the optimum size of the peer groups in the PNNI network. Both flat and multi-level networks may be designed using the methods described.
Claims2
A method for constructing a two level private network-to-network interface (PNNI) network, the PNNI network comprising a plurality of nodes N, comprising dividing the nodes into a number of nodes x*1 interconnected in each level one peer group and a number x*2 of level one peer groups, and interconnecting the level one peer groups, wherein the number of nodes x*1 interconnected in each level one peer group is determined using the following steps:
- (1) Set s=( s1, s2) such that e s1e s2=N, and set t such that e s1+γ0e(γ s1+ s2)=e t,
- (2) set f2( s, t)=eα t+κ0e(α s1+κ s2), set ε1=eα t/f2( s, t) and ε2=κ0e(α s1+κ s2)/f2( s, t),
- (3) define δ=(δ1, δ2, δ3, δ4) by
- δ
- 1
- =
- 1
- ,
- δ
- 2
- =
- ε
- 1
-
- α
-
- (
- 1
- -
- γ
- )
- +
- ε
- 2
-
- (
- κ
- -
- α
- )
- 2
- -
- γ
- ,
- δ
- 3
- =
- ε
- 1
-
- α
- -
- δ
- 2
- ,
-
- δ
- 4
- =
- ε
- 1
-
- α
- +
- ε
- 2
-
- κ
- -
- δ
- 2
- ,
- (4) set b1=log(N), b2=log (δ2/(δ1α)), b3=log (δ3/(γ0ε1α)), define (s, t)=(s1, s2, t) by
- s1=(b1+b2−b3)/(2−γ), s2=b1−si, t=s1−b2,
- and set d=(s, t)−( s, t),
- (5) set θ* to the point minimizing f2(( s, t)+θd) over the range 0≦θ≦1,
- and set ( s, t)←( s, t)+θ*d,
- (6) set x1*=e s1 and x2*=e s2
- where S1 represents the log of the number of nodes in each level one peer group, S2 represents the log of the level one peer groups, e is the numerical constant, N is the total given number of nodes in the network, α represents the time complexity of computing a minimum cost path in a flat network, γ and γ0 are constants characterizing the number of border nodes of each level one peer group, κ and κ0 characterize the number of lower level peer groups in each higher level peer group that is visited by a network connection, and f2, ε1, ε2,t, t, d, b1, b2,b3, and Θ are temporary variables.
A method for constructing a three level private network-to-network interface (PNNI) network, the PNNI network comprising a plurality of nodes N , comprising dividing the nodes into a number x*1 of lowest level nodes interconnected in each level one peer group, a number x*2 of level one peer groups in each level two peer group, and a number x*3 of level two peer groups, and interconnecting the level one peer groups and the level two peer groups, wherein the number x*1 of lowest level nodes interconnected in each level one peer group is determined using the following steps:
- (1) Set s=( s1, s2, s3) such that e s1e s2e s3=N, and set t such that e s1+γ0e(γ s1+ s2)+γ0e(γ( s1+ s2)+ s3)=e t,
- (2) set f3( s, t)=α0eα t+α0κ0e(α s1+κ s2)+κ0ω0e(ω( s1+ s2)+κ s3), set ε1=α0eα t/f3( s, t), ε2=α0κ0e(α s1+κ s2)/f3( s, t), ε3=κ0ω0e(ω( s1+ s2)+κ s3)/f3( s, t),
- set (α1, α2, α3, α4)=(ε2α+ε3ω, ε2κ+ε3ω, ε3κ1ε1α),
- (3) define δ=(δ1, δ2, δ3, δ4, δ5) by δ1=1, δ3=[(1−γ)(α1+α4)+(γ−2)α2+α3]/(γ2−3γ+3), δ2=(1−γ)δ3+α2−α1, δ4=α4−δ2−δ3, and δ5=α2+δ3+γδ4,
- (4) set π=δ2+δ3+δ4, and set b1=log(N), b2=log(δ2/λ), b3=log(δ3/(γ0λ)), and b4=log(δ4/(γ0λ)), define (s, t)=(s1, s2, s3, t) by
- s1=[b1+b2(2−γ)+b3(γ−1)−4]/(γ2−3γ+3), t=s1−b2, s2=b3+t−γs1,
- and s3=b1−s1−s2, set d=(s, t)−( s, t)
- (5) set θ* to the point minimizing f3(( s, t)+θd) over the range 0≦θ<1,
- and set ( s, t)←( s, t)+θ*d,
- (6) set x1*=e s1, x2*=e s2 and x3=e s3,
- where S1 represents the log of the number of nodes in each level one peer group, S2 represents the log of the level one peer groups, S3 represents the log of the number of level two peer groups, i is the numerical constant, N is the total given number of nodes in the network, α represents the time complexity of computing a minimum cost path in a flat network, γ and γ0 are constants characterizing the number of border nodes of each level one peer group, κ and κ0 characterize the number of lower level peer groups in each higher level peer group that is visited by a network connection, and f3, ε1, ε2,t, t, d, b1, b2,b3, b4, a1 to a4 a, ω, δ, γ, and Θ* are temporary variables.
Dependencies are inferred from the claim text.