6 Content of the protocol

The report must include the title of this work, its purpose, the results of homework: a frame structure of a multi-protocol encapsulation, the structure of the LAN / Ethernet frame encapsulation into the Frame Relay, the frame structure of the encapsulation of IP datagrams into the Frame Relay, the scheme of the Frame Relay and X.25 protocols interaction, an example of the IP datagrams fragmentation into the Frame Relay frames, the results of the laboratory setting: results of a simple analysis of multi-protocol traffic routes in the Frame Relay network, an analysis of encapsulated traffics by Novell NetWare, Ethernet / SNA and IP in the Frame Relay network in the representation of Sniffer Expert and ParaScope 2000 analyzers, the conclusions on the done work.

7 Literature

7.1. И.Г. Бакланов. ISDN и FRAME RELAY :технология и практика измерений.- М.: “ЭКО-ТРЕНДЗ”, 2000.

7.2. В. Г. Олифер, А. Н. Олифер. Компьютерные сети. С-Пб.:, 2000.

8 Appendix

8.1 Analysis of the encapsulated traffic

In the trace of Frame Relay messages and encapsulated traffic of higher levels protocols two approaches got spread in forming of the route. The first approach assumes the presence of a specialist working with the route, complete knowledge about the structure of the protocol, structure of all elements of information, etc. In this case, tracing protocol is executed up to bit. Usually, the values ​​of bits are represented in a form suitable not only for the analysis, but for the location in the information field. This approach provides routes with a maximum detailisation. These routes can be successfully used both in the development of data transmission equipment, and at the operational dimensions. Negative factor here is the need for deep knowledge about the structure of the protocol for operating personnel and a large redundancy of information in the route, which often makes it difficult to understand. As an example, such routes will be presented below by Sniffer Expert protocol analyzer developed by Company Network General Corp.

The second approach focuses on the making of operational measurements. Routes that are generated in this case, reflect only the most essential messages and information elements for signal exchange. As a result, information redundancy, which occurs in the first approach, is reduced. In addition, the requirements for speed of analyzers is decreased and, consequently, their cost. As a negative factor here is the inability to use such analyzers for measuring during the development of data transmission equipment, as well as in the case of incorrect implementation of the protocol (route identifies the incorrect implementation of the protocol, but does not specify exactly, which bits are incorrect values; in practice such cases aren’t usually met). As an example such operational routes will be presented below the route analyzer ParaScope2000 produced by Frederick Engineering Inc.

As an example of the analysis of the encapsulated traffic, let’s consider the analysis of a hypothetical data network linking two or more local area networks (Figure 8.1).

Рис. 8.1 Scheme of high-levels protocol encapsulations (NetWare)

At combining of local networks, measuring physical channel can include virtual connections, which transmit the encapsulated information of the various protocols (in general, in the PD networks there are used about 100 ... 150 or more of different protocols and modifications). As a result, multi-protocol exchange, route of the Frame Relay protocol will contain encapsulated message of various protocols (route 1).

Route 1 An example of simple route of multi-protocol-traffic in the Frame Relay network (Sniffer Expert analyzer)

SUMMARY	Delta Т	Destination	Source	Summary
1		44135046.FFFF	44135046 .Wllf	XNS RIP response: 10 networks, 20850301 at 2 hops, 20850302 at 2 hops
2	0.1982	BOOMER1	9943AC.3Com	NCPC Create Connection
3	0.0624	9943AC.3Com	BOOMER1	NCPROK
4	0.3588	000000219001	000000219002	SNAP Ethernet Type=80FF
5	0.0732	BRUTUS1	9943AC.3Com	NCPC Create Connection
6	0.0917	9943AC.3Com	BRUTUS1	NCPROK
7	1.0991	000000218001	000000218002	SNAP Ethernet Type=80FF
8	0.1960	000000208501	000000208502	SNAP Ethernet Type=80FF
9	0.1039	BUSTER1	9943AC.3Com	NCPC Create Connection
10	0.0788	9943AC.3Com	BUSTER1	NCPROK
11	0.1228	000000225001	000000225002	SNAP Ethernet Type=80FF
12	0.3411	BOOMER1	9943AC.3Com	NCPC Create Connection
13	0.0639	9943AC.3Com	BOOMERl	NCPROK
14	0.1651	000000208502	000000208501	SNAP Ethernet Type=80FF
15	0.1342	000000208501	000000208502	SNAP Ethernet Type=80FF
16	0.1297	BRUTUS1	9943AC.3Com	NCPC Create Connection
17	0.0867	9943AC.3Com	BRUTUS1	NCPROK
18	0.3134	000000219001	000000219002	SNAP Ethernet Type=80FF
19	0.2690	000000225D02	000000225001	SNAP Ethernet Type=80FF
20	0.1020	000000225001	000000225002	SNAP Ethernet Type=80FF
21	0.7196	BUSTERl	9943AC.3Com	NCPC Create Connection
22	0.0780	9943AC.3Com	BUSTER1	NCPROK
23	0.0950	000000218001	000000218002	SNAP Ethernet Type=80FF
24	0.2452	(X. Y. 1.255]	[X.Y. 1.2]	RIP R Routing entries=10
25	0.1244	BOOMERl	9943AC.3Com	NCPC Create Connection
25	0.0654	9943AC.3Com	BOOMERl	NCPROK
26	0.3716	[X.Y.1.255]	[X.Y.1.2]	RIP R Routing entries=10
28	0.0559	BRUTUS1	9943AC.3Com	NCPC Create Connection
27	0.0919	9943AC.3Com	BRUTUS1	NCPROK
30	0.2400	000000208501	000000208502	SNAP Ethernet Type=80FF
31	0.3212	000000225001	000000225002	SNAP Ethernet Type=8OFF
32	0.2201	000000219001	000000219002	SNAP Ethernet Type=80FF
33	0.6175	BUSTER1	9943AC.3Com	NCPC Create Connection
34	0.0791	9943AC.3Com	BUSTERl	NCPROK
35	0.4636	BOOMERl	9943АС. 3Com	NCP С Create Connection
35	0.0623	9943AC.3Com	BOOMERl	NCPROK
37	0.0395	000000218001	000000218002	SNAP Ethernet Type=80FF
38	0.2718	44135044.FFFF	44135046.Wllf	XNS RIP response: 12 networks, 00210101 at 2 hops, 00210102 at 2 hops
39	0.1194	BRUTUS1	9943AC.3Com	NCPC Create Connection
40	0.0870	9943AC.3Com	BRUTUS1	NCP R OK
41	0.2379	NFIDC08	4.1	XNS NetWare Security
42	0.1271	701B.00608CB8	7107F2.1	NDIAG IPX Config request
43	0.3489	000000208501	000000208502	SNAP Ethernet Type=80FF
44	0.2054	DCE.DLCI.O	DTE.DLCI.O	LMI Keep Alive Status Enquiry
45	0.0086	DTE.DLCI.O	DCE.DLCI.O	LMI Keep Alive Status
46	0.1015	000000225001	000000225002	SNAP Ethernet Type=80FF
47	0.2326	000000219001	000000219002	SNAP Ethernet Type=80FF
48	0.1418	BUSTERl	9943AC.3Com	NCPC Create Connection
49	0.0782	9943AC.3Com	BUSTERl	NCPROK
50	0.4645	BOOMERl	9943AC.3Com	NCPC Create Connection

As can be seen from the route, among messages, which are sent through the point of measurement, there are a variety of high-level protocols, including routing protocol RIP (Routing Information Protocol), which is used for Xerox Network Systems (XNS) network, the main NetWare networks protocol (NCP - NetWare Core Protocol), the diagnostics protocol of NetWare networks (NDIAG), the RIP protocol, which is used for exchanging in TCP / IP protocol, the SNAP protocol, which is used to encapsulate data traffic from the LAN. In addition, the route contains control information LMI (posts 44, 45), which was seen in the lab number 5. It should be noted that in order to preserve the confidentiality of the IP, address in the route is replaced by X and Y.