Chapter 2 MPLS Label Distribution

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Exercise 2.1: Control - Ordered or Not

In this case study, you will choose the better of two solutions for your network and justify your choice.

1.	Consider the following scenario. Your team is a group of highly paid consultants for a small, developing country. MPLS technology has been selected because of its traffic-engineering capabilities. This system will require traffic engineering to help manage increases in traffic as the network grows. On the Web, research the benefits and drawbacks of ordered control vs. non-ordered control; then recommend a solution for the LDP protocol. What are your recommendations ?
2.	Now do the following:Answer the following questions. List your references. List the advantages of ordered control. List the disadvantages of ordered control. List the advantages of non-ordered control. List the dsadvantages of non-ordered control.

Answers

1.

This group exercise and case study were designed for real-time study. The information listed below may change over time, so it is recommended that this research be conducted by each student of this course Ordered control vs. independent control was not an issue at the time - just as cut-through switches vs. store and forward switches were not issues. The technology has advanced significantly since the start of MPLS. Currently several manufacturers offer independent control for start-up and ordered control after the network links are established

2.

http://cell-relay.indiana.edu/mhonarc/mpls/2000-Jan/msg00144.html www.cis.ohio-state.edu/~jain/talks/ftp/mpls_te/sld018.htm http://rfc-3353.rfc-index.net/rfc-3353-23.htm https://dooka.canet4.net/c3_irr/mpls/sld034.htm http://course.ie.cuhk.edu.hk/~ine3010/lectures/3010_7.ppt Traffic engineering Speed set-up speed Setup speed Loss of traffic engineering

Exercise 2.2: Label Distribution

In this exercise, you will work with RFC 3036 and translate LDP messages. Use RFC 3036 to find the correct answers.

1.	Match the correct message type number in hex to the correct title of the message by recording the correct message number in the space provided. Message type numbers available for selection are: 0001, 0100, 0200, 0201, 0300, 0301, 0400, 0401, 0402, 0403, 0404 ____  Address Message ____  Address Withdraw ____  Hello ____  Initialization ____  Keep Alive ____  Label Abort Request ____  Label Release ____  Label Request ____  Label Withdraw Message ____  Labels (Series) ____  Notification
2.	Type Length Values (TLVs) are a subset of LDP messages. Match the correct TLV number in hex to the correct title of by recording the correct message number in the space provided.TLV numbers available for selection are: 0101, 0103, 0104, 0201, 0202, 0300, 0400 ____  ADDRESS LIST ____  ATM ____  FRAME RELAY ____  HOP COUNT ____  KEEP ALIVE ____  PATH LINK ____  STATUS
3.	In the hello message in Figure 2.19, fill in the message type number and the TLV number. Figure 2.19: Hello Message for Exercise 2.2

Answers

1. 

See Section 3.7 of RFC 3036.

0300  Address Message

0301  Address Withdraw

0100  Hello

0200  Initialization

0201  Keep Alive

0404  Label Abort Request

0403  Label Release

0401  Label Request

0402  Label Withdraw Message

0400  Labels (Series)

0001  Notification

2. 

Please refer to the tables in the following answer explanation.

0101  ADDRESS LIST

0201  ATM

0202  FRAME RELAY

0103  HOP COUNT

0400  KEEP ALIVE

0104  PATH LINK

0300  STATUS

The following tables are from the reference sheets for RFC 3036.

A reference sheet from RFC 3036

Message Name	Type	Section Title
Notification	0x0001	Notification Message
Hello	0x0100	Hello Message
Initialization	0x0200	Initialization Message
KeepAlive	0x0201	KeepAlive Message
Address	0x0300	Address Message
Address Withdraw	0x0301	Address Withdraw Message
Label Mapping	0x0400	Label Mapping Message
Label Request	0x0401	Label Request Message
Label Withdraw	0x0402	Label Withdraw Message
Label Release	0x0403	Label Release Message
Label Abort Request	0x0404	Label Abort Request Message
Vendor-Private	0x3E00-0x3EFF	LDP Vendor-private Extensions
Experimental	0x3F00-0X3FFF	LDP Experimental Extensions

3. 

TLV Summary

TLV	Type	Section Title
FEC	0x0100	FEC TLV
Address List	0x0101	Address List TLV
Hop Count	0x0103	Hop Count TLV
Path Vector	0x0104	Path Vector TLV
Generic Label	0x0200	Generic Label TLV
ATM Label	0x0201	ATM Label TLV
Frame Relay Label	0x0200	Frame Relay Label TLV
Status	0x0300	Status TLV
Extended Status	0x0301	Notification Message
Returned PDU	0x0302	Notification Message
Returned Message	0x0303	Notification Message
Common Hello	0x0400	Hello Message
IPv4 Transport Address	0x0401	Hello Message
Configuration	0x0402	Hello Message
IPv6 Transport Address	0x0403	Hello Message
Common Session	0x0500	Initialization Message
ATM Session Parameters	0x0501	Initialization Message
Frame Relay Session	0x0502	Initialization Message
Label Request	0x0600	Label Mapping Message
Vendor-Private	0x3E00-0X3EFF	LDP Vendor-private Extensions

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