Book on Network Architecture and Design

Fellow NANOGers, I am in search of a good book about Network Architecture and Design, with emphasis in Quality of Service and convergent networks, to be used as a reference. Could you please indcate your favorites? -- Abraços, Marlon Borba, CISSP, APC DataCenter Associate Técnico Judiciário - Segurança da Informação IPv6 Evangelist TRF 3 Região (11) 3012-1000 r. 5678 -- Practically no IT system is risk free. (NIST Special Publication 800-30) -- IPv6: só 96 bits a mais (Comitê Gestor da Internet Brasil) --