  We study dynamics of triple junction of (p,q) strings in Type IIB string
theory. We probe tension and mass density of (p,q) strings by studying harmonic
fluctuations of the triple junction. We show that they agree perfectly with BPS
formula provided suitable geometric interpretation of the junction is given. We
provide a precise statement of BPS limit and force-balance property. At weak
coupling and sufficiently dense limit, we argue that (p,q)-string embedded in
string network is a `wiggly string', whose low-energy dynamics can be described
via renormalization group evolved, smooth effective non-relativistic string. We
also suggest the possibility that, upon Type IIB strings are promoted to
M-theory membrane, there can exist `evanescent' bound-states at triple junction
in the continuum.
