set u2208 and v nodes to facilitate our description we will use a tuple s u2192 d w to represent a new request for connection establishment or release where s and d are the source or ingress and destination or egress of the connection respectively and w is the bandwidth in units requested by the connection g set of shared risk link group srlg g a this is the union of the srlg 39 s to which the links along the ap belong a e set of connections whose aps traverse link e a e u2211 k u2208 a e u2062 u2062 w k u2062 u2062 total i e aggregated abw on link e dedicated to the connections in a e b e set of connections whose bps traverse link e b e total bbw allocated on line e for b e do bbw sharing r e residue bandwidth of link e its initial value is equal to the capacity of link e c e r e c e u2212 a e u2212 b e with only protected connections s g e total amount of bandwidth required by the set of connections whose aps traverse any link in srlg g and whose bps traverse link e bc g e additional bbw needed on link e in order to use it as part of a bp for a new connection whose ap traverses link in srlg g its value depends on which bbw estimation method is used bc e estimated bbw needed on link e along a new bp assuming that its corresponding ap and g a is known bc e max u2200.