Table 1 List of notations
From: Control plane delay minimization-based capacitated controller placement algorithm for SDN
Notations | Description |
|---|---|
V | The set of switches |
C | The set of controllers |
Φ | The set of controller capacity |
v0 | The propagation velocity of electromagnetic wave |
β | The average size of signaling messages |
μi | The capacity of Ci |
li | The signaling load of Ci |
\(D_{j}^{\max }\) | The maximum tolerable control plane delay of Vj |
Ψj | The candidate controller set of Vj |
λj | The average arrival rate of the signaling messages sent from Vj |
Hij | The total hops of the link between Vj and Ci |
\(L_{ij}^{h}\) | The length of the hth hop link between Vj and Ci |
\(R_{ij}^{h}\) | The transmission rate of the hth hop link between Vj and Ci |
α | Weighting factor for the importance of inter-controller delay |
αij | Connection state variable between Vi and Vj |
xij | Association variable between Vj and Ci |
zim | Capacity matching variable between Ci and Ï•m |
yi | Controller placement variable at Ci |
θkn | The route selection variable between adjacent switches V k and V n |
D | The control plane delay of the network |
Ds | The delay between controllers and switches |
Dc | The inter-controller delay |
\(D_{ij}^{\mathrm {p}}\) | The propagation delay between V j and C i |
\(D_{ij}^{\mathrm {t}}\) | The transmission delay between V j and C i |
\(D_{i}^{\mathrm {w}}\) | The signaling processing time at C i |
\(D_{ij}^{\mathrm {c,p}}\) | The propagation delay between C i and C j |
\(D_{ij}^{\mathrm {c,t}}\) | The transmission delay between C i and C j |