WINNIPEG - John A. MacDonald, president of MTS Allstream's Enterprise Solutions division, will retire after six years with the company, it was announced Wednesday. This will conclude a 30-year career as a senior executive in the Canadian telecommunications industry. The Enterprise Solutions division, which operates under the Allstream brand nationally, competes in the national business and wholesale telecommunications markets. After beginning his career as an engineer at the New Brunswick telephone company NB Tel, MacDonald progressed up the management ranks to become president. Among his other senior executive positions were chief technology officer and chief operating officer of Bell Canada,...