Dear fellows: We are designing a backplane for a high-speed transmission telecom equipment. The highest speed running on this backplane is 155Mbits/sec. My colleague who has a little experience of designing a previous backplane used in a lower speed one suggests me that, a pre-layout by manual (paper and pencil) absolutely necessary for having a trace check before being submitted into real layout. Anyway, I don't think it is a good idea because it takes too much efforts, unfortunately, I am agree with that a pre-check is needed but I don't know is there any better way? Anyway comments from you? C.-F. Huang ################################################################ DesignerCouncil E-Mail Forum provided as a free service by IPC using LISTSERV 1.8c ################################################################ To subscribe/unsubscribe, send a message to [log in to unmask] with following text in the body: To subscribe: SUBSCRIBE DesignerCouncil <your full name> To unsubscribe: SIGNOFF DesignerCouncil ################################################################ Please visit IPC web site (http://jefry.ipc.org/forum.htm) for additional information. For the technical support contact Dmitriy Sklyar at [log in to unmask] or 847-509-9700 ext.311 ################################################################