Software　Defined　Optical　Network　(SDON)　can　be　considered　as　extension　of　Software　Defined　Network　(SDN)　in　optical　networks.　SDON　offers　a　unified　control　plane　and　makes　optical　network　an　intelligent　transport　network　with　dynamic　flexibility　and　service　adaptability.　For　this　reason,　a　comprehensive　optical　transmission　service,　able　to　achieve　service　differentiation　all　the　way　down　to　the　optical　transport　layer,　can　be　provided　to　service　function　chaining　(SFC).　IP　over　optical　network,　as　a　promising　networking　architecture　to　interconnect　data　centers,　is　the　most　widely　used　scenarios　of　SFC.　In　this　paper,　we　offer　a　flexible　and　dynamic　resource　allocation　method　for　diverse　SFC　service　requests　in　the　IP　over　optical　network.　To　do　so,　we　firstly　propose　the　concept　of　optical　service　function　(OSF)　and　a　multi-layer　SFC　model.　OSF　represents　the　comprehensive　optical　transmission　service　(e.g.,　multicast,　low　latency,　quality　of　service,　etc.),　which　can　be　achieved　in　multi-layer　SFC　model.　OSF　can　also　be　considered　as　a　special　SF.　Secondly,　we　design　a　resource　allocation　algorithm,　which　we　call　OSF-oriented　optical　service　scheduling　algorithm.　It　is　able　to　address　multi-layer　SFC　optical　service　scheduling　and　provide　comprehensive　optical　transmission　service,　while　meeting　multiple　optical　transmission　requirements　(e.g.,　bandwidth,　latency,　availability).　Moreover,　the　algorithm　exploits　the　concept　of　Auxiliary　Graph.　Finally,　we　compare　our　algorithm　with　the　Baseline　algorithm　in　simulation.　And　simulation　results　show　that　our　algorithm　achieves　superior　performance　than　Baseline　algorithm　in　low　traffic　load　condition.