The most common test to the test centre:
Cisco 642-425: CCVP IP Telephony Troubleshooting, these are some exam study guides which you will cover every field and category in CCVP helping to ready you for your successful Cisco Certification.
Cisco 642-532: Securing Networks Using Intrusion Prevention Systems Exam (IPS), these are some exam study guides which you will cover every field and category in CCSP helping to ready you for your successful Cisco Certification.
Cisco 642-542: Cisco SAFE Implementation Exam, these are some exam study guides which you will cover every field and category in CCSP helping to ready you for your successful Cisco Certification.
Microsoft 70-291: MCDBA Implementing, Managing, and Maintaining a Microsoft Windows Server 2003 Network Infrastructure, these are some exam study guides which you will cover every field and category in MCDBA helping to ready you for your successful Microsoft Certification.
Microsoft 74-135: Developing E-Business Solutions Using MS BizTalk Server2004, these are some exam study guides which you will cover every field and category in Microsoft Partner Competency exam helping to ready you for your successful Microsoft Certification.

(A) OSI seven structure: the role of each floor need to know, all belonging to the various applications and data flow through a layer of each layer at the (top-down, bottom-up) increases HERDER situation and Chaibao .
(B) Frame Relay (FRAMERELAY) Application: CCNA certification examinations as the frame relay wide area network (WAN) as part of the test. You will encounter in the examination of the contents of a large number of Frame Relay. Therefore, you must be prepared to pay particular attention to the study of frame relay.
(C) ISDN: know if TE-1, TE-2, NT-1, U interface (U-INTERFACE), B-CHANNAL, D-CHANNAL and a number of sub-channel (SUB-CHANNAL), and other terms (ISDN related to The terms and abbreviations in particular, must know their meaning and effect), BRI and PRI know the difference between.
(D) clearly AccessList: DenyAccesslist understanding of the inflow and outflow of data flow constraints, DENYALL clearly implied meaning. Can skillfully through the set limit on the subnet mask sub-users.
(5) Ethernet switch: familiar with Ethernet switch and exchange of principles, understanding the conflict network sub-domain principle and VLAN.