Figure 4-3 shows the DB-60 end of a serial cable that connects to a 2500 series router.
Figure 4-3. Serial Cable (2500)
Figure 4-4 shows the newer smart serial end of a serial cable that connects to a smart serial port on your router.
Figure 4-4. Smart Serial Cable (1700 or 2600)
Figure 4-5 shows examples of the male data terminal equipment (DTE) and the female data communications equipment (DCE) ends that are on the other side of a serial or smart serial cable.
Figure 4-5. V.35 DTE and DCE Cables
Laptops released in the past few years come equipped with USB ports, not serial ports. For these newer laptops, you need a USB-to-serial connector, as illustrated in Figure 4-6.
CCNA focuses on V.35 cables for back-to-back connections between routers.
Figure 4-6. USB-to-Serial Connector for Laptops