mpls basics

1C Q F E re v 17 R u s s D a v is © 1 9 9 9 , C is c o S y s te m s , In c .

B A S IC M P L SB A S IC M P L S

2C Q F E re v 14 R u s s D a v is © 1 9 9 9 , C is c o S y s te m s , In c . w w w .C is c o .c o m

A g e n d aA g e n d a

• E a r lie r S w itc h in g m o d e s

P r o c e s s S w itc h in g

F a s t s w itc h in g

C is c o E x p r e s s fo r w a r d in g

• M u lti P r o to c o l L a b e l S w itc h in g


A g e n d aA g e n d a

• M u lti P r o to c o l L a b e l S w itc h in gM P L S C o n c e p ts

L S R s a n d la b e ls

L a b e l a s s ig n m e n t a n d d is tr ib u tio n

L a b e l S w itc h P a th s

A T M L S R s

L o o p d e te c tio n /p r e v e n tio n

L D P c o n c e p ts

C o n fig u r a tio n s


P r o c e s s S w itc h in gP r o c e s s S w itc h in g

• P r o c e s s c o n te x t

• E a r lie s t C is c o IO S ™ s w itc h in g m o d e

• L e a s t p e r fo r m a n c e

• U s e s IP r o u tin g ta b le


D e p lo y m e n t In fo r m a tio nD e p lo y m e n t In fo r m a tio n

• A v a ila b le in a ll p la tfo r m s

• A v a ila b le b y d e fa u lt


F a s t S w itc h in gF a s t S w itc h in g

• R e c u r s io n r e s o lu tio n a t p r o c e s s le v e l

• C la s s fu ll

• P e r -d e s tin a tio n lo a d s h a r in g

• C a c h e e n tr ie s a g e d to lim it th ec a c h e s iz e


F a s t S w itc h in gF a s t S w itc h in g

• O v e r h e a d in h e r e n t to c a c h e m a in te n a n c e

R o u te c h a n g e

In te r fa c e s ta te c h a n g e

C o n fig u r a tio n c h a n g e

• A s s u m e s fin ite n u m b e r o fa c tiv e flo w s


O p tim u m S w itc h in gO p tim u m S w itc h in g

• E x te n s io n o f fa s t s w itc h in g

• O p tim u m c a c h e

• O p tim iz e d fo r h ig h e r p e r fo r m a n c e

• S a m e is s u e s

• D e p r e c a te d in C is c o IO S 1 2 .0


R S P

V IP

IP

F ir s t P a c k e t

S u b s e q u e n t P a c k e ts

D is tr ib u te d F a s t S w itc h in gD is tr ib u te d F a s t S w itc h in g

• A v a ila b le w ith in te llig e n t IP s

• D is tr ib u te d c a c h e


E v o lu tio n : S P DE v o lu tio n : S P D

• S e le c tiv e P a c k e t D is c a r d

• M a jo r r o u te c h a n g ec a u s e s c a c h e c h u r n

• T r ig g e r s la r g e n u m b e r o f p a c k e ts to p r o c e s s le v e l

• O v e r w h e lm s C P U a n dc a u s e s c o n tr o lp a c k e t d r o p

• C a u s e s p r o lo n g e din s ta b ility

• S P D to d iffe r e n tia tec o n tr o l tr a ffic

• P r e c e d e n c e b it u s e d to m a r k c o n tr o l p a c k e ts(e .g . B G P u p d a te s )

• A v o id s d r o p p in gc o n tr o l p a c k e t

• In c r e a s e d s y s te ms ta b ility


C is c o E x p r e s s F o r w a r d in gC is c o E x p r e s s F o r w a r d in g

• N e w to p o lo g y d r iv e n a r c h ite c tu r e

• M a in c o m p o n e n ts

F o r w a r d in g In fo r m a tio n B a s e (F IB )

A d ja c e n c y ta b le

• N o p r o c e s s s w itc h in g o f p a c k e ts



• F o r w a r d in g In fo r m a tio n B a s e

• A d ja c e n c y D a ta b a s e


F IB T a b leF IB T a b le

• S h a d o w c o p y o f th e IP r o u tin g ta b le• C la s s le s s• R o u tin g p r o to c o l in d e p e n d e n t • O n e fo r e a c h r o u te in IP r o u tin g ta b le• E a c h e n tr y h a s o n e o r m o r e p a th• E a c h p a th h a s n e x th o p IP a d d r e s s a n d

n e x th o p in te r fa c e• E a c h p a th p o in ts to a n a d ja c e n c y


A d ja c e n c y T a b leA d ja c e n c y T a b le

• M a in ta in s IP a d d r e s s toM a c -r e w r ite m a p p in g

• P o p u la te d b y A R P ta b le , F r a m e R e la y m a p ta b le a n d A T M m a p ta b le , e tc .

• M a c -r e w r ite o f th e n e x th o p is a ll th a t’s r e q u ir e d to s w itc h p a c k e t



• N o r m a l: C a c h e , G le a n , H o s t-R o u te

• S p e c ia l: D r o p , P u n t, In c o m p le te



• N o r m a l

C a c h e : N e x t H o p

G le a n : In s ta ll a d ja c e n c y fo r s u b n e t o f d ir e c tly c o n n e c te d n e tw o r k s

H o s t r o u te : If d ir e c tly c o n n e c te d n e tw o r k th e n A R P w ill in s ta ll h o s t r o u te a d ja c e n c y . P 2 P lin k s g e ts h o s t r o u te a u to m a tic a lly



• S p e c ia l

P u n t: IP o p tio n u n s u p p o r te d fe a tu r e

D r o p : F a s t d r o p , e x a m p le N u ll in te r fa c e

In c o m p le te : E r r o r s ta te (W h e n lin k g o e s d o w n )


F IBT a b leF IBF IB

T a b leT a b leA d ja c e n c y

T a b leA d ja c e n c y A d ja c e n c y

T a b leT a b le


R o u tin gR o u tin gT a b leT a b le

A R P /M a pT a b le

A R P /M a pA R P /M a pT a b leT a b le


C E F O p e r a tio nC E F O p e r a tio n

• F IB e n tr y c r e a te d w h e n r o u te sa r e a d d e d to IP r o u tin g ta b le

• If c o n n e c te d , n e w F IB e n tr y p o in tsto th e c o r r e s p o n d in g a d ja c e n c y

• R e a d y to s w itc h p a c k e ts

• N o n -c o n n e c te d p r e fix r e q u ir e sm o r e w o r k

2 0C Q F E re v 14 R u s s D a v is © 1 9 9 9 , C is c o S y s te m s , In c . w w w .C is c o .c o m

C E F O p e r a tio nC E F O p e r a tio n

• R e c u r s io n r e s o lu tio n

• D o n e in th e b a c k g r o u n d

• R e c u r s iv e lo o k u p fo r n o n -c o n n e c te d n e x th o p to fin d th e c o n n e c te d n e x th o p

• O n c e r e s o lv e d , r e a d y to s w itc h


D e s tin a tio n

S o u r c e s

C E F L o a d -S h a r in gC E F L o a d -S h a r in g

• P e r p a c k e t a n d e n h a n c e d p e r d e s tin a tio n• E n h a n c e d p e r d e s tin a tio n is b a s e d o n s o u r c e a n d

d e s tin a tio n IP a d d r e s s e s• E a c h d e s tin a tio n flo w ta k e s a s in g le , s e p a r a te p a th• R e d u c e s n e e d fo r p e r p a c k e t lo a d -s h a r in g


M P L S C o n c e p tsM P L S C o n c e p ts

• S e p a r a tio n o f r o u tin g a n d fo r w a r d in g

• F o r w a r d in g is d o n e in d e p e n d e n tly

• In te g r a te s th e c o n tr o l o f IP r o u tin g w ith s im p lic ity o f la y e r 2 s w itc h in g

• H e lp s in d e p lo y m e n t o f c o m p lic a te d r o u tin g s e r v ic e s



• S e p a r a tio n o f c o n tr o l a n d fo r w a r d in g

C o n tr o l is b u ild b y s ta n d a r d r o u tin g p r o to c o ls (O S P F ,IS IS ,B G P )

F o r w a r d in g is b u ild b y L D P in d e p e n d e n t o f r o u tin g p r o to c o ls



• F o r w a r d in g E q u iv a le n c e C la s s (F E C )

G r o u p o f IP p a c k e ts fo r w a r d e d w ith s a m e tr e a tm e n t o v e r th e s a m e p a th ir r e s p e c tiv e o f th e fin a l d e s tin a tio n

P a c k e t is a s s ig n e d to F E C b a s e d o n its n e tw o r k la y e r d e s tin a tio n a d d r e s s



• F E C19 8 .10 .0 .0 /16

14 0 .10 .1.1

14 0 .10 .1.2

H 1

H 2


• L a b e l

L a b e l is a s h o r t fix e d le n g th , lo c a lly s ig n ific a n t u s e d to id e n tify a F E C

L a b e l is a s s ig n e d o n th e n e tw o r k la y e r a d d r e s s b u t it is n o t e n c o d in g o f th e n e tw o r k la y e r a d d r e s s

L a b e l h a s lo c a l s ig n ific a n c e b e tw e e n L S R ’s




• L a b e le d P a c k e t

P a c k e t in to w h ic h a la b e l h a s b e e n e n c o d e d

L a b e l c o u ld r e s id e in s id e n e tw o r k o r d a ta lin k la y e r (A T M )



• U p s tr e a m

W h e r e th e p a c k e t s o u r c e is

• D o w n s tr e a m

T o w a r d s th e d e s tin a tio n


U p s tr e a m a n d D o w n s tr e a m L S R s

• R tr -C is th e d o w n s tr e a m n e ig h b o u r o f R tr -B fo r d e s tin a tio n 1 7 1 .6 8 .1 0 /2 4

• R tr -B is th e d o w n s tr e a m n e ig h b o u r o f R tr -A fo r d e s tin a tio n 1 7 1 .6 8 .1 0 /2 4

• L S R s k n o w th e ir d o w n s tr e a m n e ig h b o u r s th r o u g h th e IP r o u tin g p r o to c o lN e x t-h o p a d d r e s s is th e d o w n s tr e a m n e ig h b o u r

1 7 1 .6 8 .1 0 /2 4

R tr -BR tr -A R tr -C1 7 1 .6 8 .4 0 /2 4



• L a b e l A s s ig n m e n t

A s s ig n m e n t is d o n e b y th e L S R d o w n s tr e a m

D o w n s tr e a m L S R in fo r m s th e u p s tr e a m L S R o f th e b in d in g



• L a b e l D is tr ib u tio n P r o to c o ls (L D P )

S e t o f p r o c e d u r e s b y w h ic h o n e L S R in fo r m s o th e r a b o u t th e la b e l fo r a c e r ta in F E C

L S R th a t d is tr ib u te la b e l in fo r m a tio n b e tw e e n e a c h o th e r a r e k n o w n a s “ L a b e l D is tr ib u tio n P e e r s ”



• M P L S a r c h ite c tu r e d o e s n o t a s s u m e a s in g le p r o to c o l

E x is tin g p r o to c o ls h a v e b e e n e x te n d e d (M P -B G P ), (M P L S -R S V P )

N e w p r o to c o ls h a v e a ls o b e e n d e fin e d (M P L S -L D P ), (M P L S -C R -L D P )


• M P L S a llo w s :

P a c k e t c la s s ific a tio n o n ly w h e r e th e p a c k e t e n te r s th e n e tw o r k

T h e p a c k e t c la s s ific a tio n is e n c o d e d a s a la b e l

In th e c o r e , p a c k e ts a r e fo r w a r d e d w ith o u t h a v in g to r e -c la s s ify th e m

N o fu r th e r p a c k e t a n a ly s is

L a b e l s w a p p in g



P a c k e ts a r e fo r w a r d e d b a s e d o n th e la b e l v a lu e

O th e r p a r a d ig m s m a y b e u s e d to fo r w a r d tr a ffic

n o n e e d to s tr ic tly fo llo w u n ic a s t d e s tin a tio n b a s e d r o u tin g

A llo w s to h a v e d is tin c t fo r w a r d in g d e c is io n b a s e d o n

D e s tin a tio n u n ic a s t r o u tin g

T r a ffic E n g in e e r in g

M u ltic a s t

V P N

Q o S

...



M P L S c o n c e p tsP a c k e t fo r w a r d in g : IP n e tw o r k s

• IP fo r w a r d in g

IP fo r w a r d in g is d o n e in d e p e n d e n tly a t e v e r y h o p

IP fo r w a r d in g d e c is io n is m a d e o n :

P a c k e t h e a d e r

R o u tin g a lg o r ith m o u tp u t (r o u tin g ta b le )

E a c h IP h o p r u n s its o w n in s ta n c e o f th e r o u tin g a lg o r ith m

E a c h IP h o p m a k e s its o w n fo r w a r d in g d e c is io n s


M P L S c o n c e p tsP a c k e t fo r w a r d in g : F E C a n d N e x t-H o p

• IP p a c k e ts a r e c la s s ifie d in F E C s

F o r w a r d in g E q u iv a le n c e C la s s

• A g r o u p o f IP p a c k e ts w h ic h a r e fo r w a r d e d in th e s a m e m a n n e r

O v e r th e s a m e p a th

W ith th e s a m e fo r w a r d in g tr e a tm e n t

• P a c k e t fo r w a r d in g c o n s is ts o n

A s s ig n a p a c k e t to a F E C

D e te r m in e th e n e x t-h o p o f e a c h F E C



• M P L S m a k e u s e o f F E C s

• M P L S n o d e s a s s ig n a la b e l to e a c h F E C

• P a c k e t c la s s ific a tio n (in to a F E C ) is d o n e w h e r e th e p a c k e t e n te r s th e c o r e

• N o s u b -s e q u e n t p a c k e t c la s s ific a tio n in th e M P L S n e tw o r k


A d d r e s s A d d r e s s P r e fix a n d m a s kP r e fix a n d m a s k

1 7 1 .6 8 .1 0 /2 41 7 1 .6 8 .1 0 /2 4

......

N e x tN e x t -- H o pH o p

1 7 1 .6 8 .9 .11 7 1 .6 8 .9 .1

......


1 7 1 .6 8 .1 0 /2 40 1

In te r fa c eIn te r fa c e

S e r ia l1S e r ia l1

......

IP p a c k e tD = 1 7 1 .6 8 .1 0 .1 2 IP p a c k e t

D = 1 7 1 .6 8 .1 0 .2 3

R o u te r -A fo r w a r d s p a c k e ts w ith d iffe r e n t d e s tin a tio n a d d r e s s e s u s in g th e s a m e r o u te , s a m e n e x t-h o p a n d s a m e in te r fa c e

R tr -A



• P a c k e ts a r e c la s s ifie d in to F E C s

• F o r e a c h F E C th e n e x t-h o p is c a lc u la te d

• In IP r o u tin g e a c h h o p :

r e -c la s s ify th e p a c k e t in to o n e F E C

r e c a lc u la te th e n e x t-h o p o f th e F E C




1 7 1 .6 8 .1 0 /2 40 1

R o u te r -A fo r w a r d s la b e lle d p a c k e ts b y lo o k in g a t th e la b e l v a lu e a g a in s t th e la b e l ta b le . N o p a c k e t c la s s ific a tio n in to F E C is d o n e .

R tr -A

In In L a bL a b

55

......

A d d r e s s A d d r e s s P r e fixP r e fix

1 7 1 .6 8 .1 01 7 1 .6 8 .1 0

......

O u tO u tI/FI/F

11

......

O u t O u t L a bL a b

33

......

In In I/FI/F

00

......

IP p a c k e tD = 1 7 1 .6 8 .1 0 .1 2

L a b e l = 5


In In L a bL a b

xx

......


1 7 1 .6 8 .1 01 7 1 .6 8 .1 0

......

O u tO u tI/FI/F

33

......


55

......

In In I/FI/F

44

......

34

IP p a c k e tD = 1 7 1 .6 8 .1 0 .1 2

R tr -B

R o u te r -B c la s s ify th e IP p a c k e t in to a F E C a n d a s s ig n th e c o r r e s p o n d in g la b e l.

IP p a c k e tD = 1 7 1 .6 8 .1 0 .1 2

L a b e l = 3


M P L S c o n c e p tsM P L S fo r w a r d in g

• M P L S fo r w a r d in g is p e r fo r m e d in th e s a m e w a y in A T M s w itc h e s a n d r o u te r s . H o w e v e r ,A T M q u e u in g is g iv e n b y th e la b e l v a lu e (V C I)

R o u te r q u e u in g m a y b e g iv e n b y “ E X P ” b its in la b e l h e a d e r

• A T M s w itc h e s d o n o t h a v e c a p a b ilitie s to a n a ly s e la y e r 3 h e a d e r s

• L a b e ls m a y b e d is tr ib u te d b y d iffe r e n t p r o to c o ls

L D P , R S V P , P IM , B G P , ...



• P a c k e t c la s s ific a tio n is d o n e a t th e in g r e s s

W h e n p a c k e t e n te r s in to th e n e tw o r k

• C la s s ific a tio n m e c h a n is m m a y b e c o m p le x

IG P

M u ltic a s t


V P N

Q o S

...



• P a c k e t fo r w a r d in g in th e c o r e is n o t a ffe c te d b y th e c o m p le x ity o f p a c k e t c la s s ific a tio n a t th e e d g e

• In fo r m a tio n n e e d e d to d o p a c k e t c la s s ific a tio n m a y n o t b e p r e s e n t in th e c o r e

• A ll c la s s ific a tio n s m a d e a r e id e n tifie d b y th e la b e l a n d /o r b y “ E X P ” b its o f th e la b e l h e a d e r


M P L S c o n c e p tsL a b e l S w itc h R o u te r s

• L S R : L a b e l S w itc h R o u te r

• C a n b e a n A T M s w itc h o r a r o u te r

• E d g e -L S R s d o la b e l im p o s itio n a n d la b e l r e m o v a l

L a b e l im p o s itio n w h e r e th e p a c k e t e n te r s th e M P L S n e tw o r k

L a b e l r e m o v a l w h e r e th e p a c k e t le a v e s th e M P L S n e tw o r k

• A ll L S R s u s e e x is tin g IP r o u tin g p r o to c o ls to e x c h a n g e r o u tin g in fo r m a tio n

• A ll L S R s u s e a la b e l d is tr ib u tio n p r o to c o lN o t n e c e s s a r ily th e s a m e in a ll L S R s


M P L S c o n c e p tsA T M -L S R

• In o r d e r to e x c h a n g e la b e ls , A T M -L S R s n e e d to r u n a n IP r o u tin g p r o to c o l

A T M -L S R s w ill a c t a s r o u te r s in te r m s o f IP c o n tr o l p la n e

A T M -L S R s w ill a c t a s A T M s w itc h e s in te r m s o f d a ta p la n e

A T M -L S R s w ill N O T r o u te p a c k e ts b a s e d o n r o u tin g ta b le

P a c k e t fo r w a r d in g is b a s e d o n la b e l in fo r m a tio n

C o n tr o l V C is u s e d to e x c h a n g e la b e ls

• A T M s w itc h e s u s e in p u t p o r t,V P I,V C I v a lu e s a n d m a p th e m to o u tp u t p o r t,V P I,V C I v a lu e s

• L a b e l is e n c o d e d in s a m e fie ld sV P I/V C I fie ld u s e d to c a r r y la b e l in fo r m a tio n

E x is tin g s o ftw a r e c a n w o r k fo r la b e l s w a p p in g


M P L S c o n c e p tsL a b e ls

• L a b e l fo r m a t a n d le n g th d e p e n d s o n e n c a p s u la tio n

• H a s to b e n e g o tia te d b e tw e e n p e e r s o v e r A T M in te r fa c e s

• M o r e th a n o n e la b e l is a llo w e dL a b e l s ta c k : o r d e r e d s e t o f la b e ls

• M P L S L S R s a lw a y s fo r w a r d p a c k e ts b a s e d o n th e v a lu e o f th e la b e l a t th e to p o f th e s ta c k



• G e n e r ic : c a n b e u s e d o v e r E th e r n e t, 8 0 2 .3 , P P P lin k s , F r a m e R e la y , A T M P V C s , e tc .

• U s e s n e w E th e r ty p e s /P P P P ID s /S N A P v a lu e s /e tc .

D iffe r e n t E th e r ty p e s fo r u n ic a s t a n d m u ltic a s t

• 4 o c te ts (p e r ta g le v e l)

L a b e l = 2 0 b its E x p = E x p e r im e n ta l, 3 b its S = B o tto m o f s ta c k , 1 b itT T L = T im e to liv e , 8 b its

0 1 2 30 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1

L a b e l | E x p |S | T T L



P P P H e a d e r(P a c k e t o v e r S O N E T /S D H )

A T M C e ll H e a d e r

L A N M A C L a b e l H e a d e r

H E CH E C D A T AD A T AC L PC L PP T IP T IV C IV C IG F CG F C V P IV P I

L a b e l

P P P H e a d e rP P P H e a d e r L a y e r 3 H e a d e rL a y e r 3 H e a d e rL a b e l

L a b e l L a y e r 3 H e a d e rL a y e r 3 H e a d e rM A C H e a d e rM A C H e a d e r

S h im h e a d e r


L a b e l a s s ig n m e n t a n d d is tr ib u tio n

• L a b e ls h a v e lo c a l s ig n ific a n c eE a c h L S R b in d s h is o w n la b e l m a p p in g s

• E a c h L S R a s s ig n la b e ls to h is F E C s

• L a b e ls a r e a s s ig n e d a n d e x c h a n g e d b e tw e e n a d ja c e n t L S R s

D o w n s tr e a m to U p s tr e a m

• A p p lic a tio n s m a y r e q u ir e n o n -a d ja c e n t n e ig h b o u r s


V P N



• R tr -C is th e d o w n s tr e a m n e ig h b o u r o f R tr -B fo r d e s tin a tio n 1 7 1 .6 8 .1 0 /2 4

• R tr -B is th e d o w n s tr e a m n e ig h b o u r o f R tr -A fo r d e s tin a tio n 1 7 1 .6 8 .1 0 /2 4

• L S R s k n o w th e ir d o w n s tr e a m n e ig h b o u r s th r o u g h th e IP r o u tin g p r o to c o lN e x t-h o p a d d r e s s is th e d o w n s tr e a m n e ig h b o u r

1 7 1 .6 8 .1 0 /2 4

R tr -BR tr -A R tr -C1 7 1 .6 8 .4 0 /2 4



• L S R s a s s ig n a la b e l to e a c h F E C

• L a b e l d is tr ib u tio n m a y b e u p s tr e a m o r d o w n s tr e a m d r iv e n

• M o s t im p le m e n ta tio n s u s e d o w n s tr e a m w ith tw o v a r ia n ts

U n s o lic ite d D o w n s tr e a m

D o w n s tr e a m o n d e m a n d

n o n e e d fo r u p s tr e a m a llo c a tio n


U n s o lic ite d D o w n s tr e a m d is tr ib u tio n


• L S R s d is tr ib u te la b e ls to th e u p s tr e a m n e ig h b o u r s

1 7 1 .6 8 .1 0 /2 4

R tr -BR tr -A R tr -C

1 7 1 .6 8 .4 0 /2 4


In In L a bL a b

--

......


1 7 1 .6 8 .1 01 7 1 .6 8 .1 0

......

O u tO u tI/FI/F

11

......


55......

In In I/FI/F

00

...... N e x tN e x t -- H o pH o p

In In L a bL a b

55

......


1 7 1 .6 8 .1 01 7 1 .6 8 .1 0

......

O u tO u tI/FI/F

11

......


77......

In In I/FI/F

00

......


In In L a bL a b

77

......


1 7 1 .6 8 .1 01 7 1 .6 8 .1 0

......

O u tO u tI/FI/F

11

......


--......

In In I/FI/F

00

......

U s e la b e l 7 fo r d e s tin a tio n 1 7 1 .6 8 .1 0 /2 4


IG P d e r iv e d r o u te s


D o w n s tr e a m o n d e m a n d d is tr ib u tio n


• U p s tr e a m L S R s r e q u e s t la b e ls to d o w n s tr e a m n e ig h b o u r s

• D o w n s tr e a m L S R s d is tr ib u te la b e ls u p o n r e q u e s t

1 7 1 .6 8 .1 0 /2 4

R tr -BR tr -A R tr -C1 7 1 .6 8 .4 0 /2 4



R e q u e s t la b e l fo r d e s tin a tio n 1 7 1 .6 8 .1 0 /2 4

R e q u e s t la b e l fo r d e s tin a tio n 1 7 1 .6 8 .1 0 /2 4


U n s o lic ite d D o w n s tr e a m v s . D o w n s tr e a m o n d e m a n d

• D o w n s tr e a m o n d e m a n d is u s e d b y A T M -L S R s a n d in tr a ffic e n g in e e r in g w ith R S V P

• A T M s w itc h e s fo r w a r d c e lls , n o t p a c k e ts

• L a b e l is c a r r ie d in V P I/V C I fie ld

• S A R p r o c e s s n e e d to d is tin g u is h p a c k e tsC e lls b e lo n g in g to d iffe r e n t p a c k e ts b u t h a v in g

th e s a m e la b e l n e e d to b e r e -a s s e m b le d c o r r e c tly

• L a b e l n e e d to b e a s s ig n e d b a s e d :o n IP d e s tin a tio n a n d in c o m in g in te r fa c e s

T r a ffic E n g in e e r in g m e c h a n is m s


D o w n s tr e a m o n d e m a n d a n d V C -M e r g e

• V C -M e r g e a llo w s c o r r e c t p a c k e t r e -a s s e m b lin g

• S e q u e n c in g o f c e lls b y b u ffe r in g

• R e c e iv in g (d o w n s tr e a m ) A T M -L S R c a n s e c u r e ly r e -a s s e m b le c e lls in to p a c k e ts

E v e n c e lls o f d iffe r e n t p a c k e ts u s e s a m e V P I/V C I v a lu e

S a v e la b e l s p a c e o n A T M -L S R s


D o w n s tr e a m o n D e m a n d a n d A T M

In In L a bL a b

55

88

......


1 7 1 .6 81 7 1 .6 8

1 7 1 .6 81 7 1 .6 8

......

O u tO u tI/FI/F

00

00

......


33

33

......

In In I/FI/F

11

22

......

1 7 1 .6 8

IPP a c k e t

IPP a c k e t A T

Mc e ll

5

A TM

c e ll

8

A TM

c e ll

8

A TM

c e ll

8

A TM

c e ll

5

A TM

c e ll

3 A TM

c e ll

3 A TM

c e ll

3 A TM

c e ll

3 A TM

c e ll

3

D o w n s tr e a m L S R d o n o t k n o w h o w to r e a s s e m b le c o r r e c tly c e lls in to p a c k e ts . V P I/V C I v a lu e s a r e id e n tic a l fo r a ll c e lls


D o w n s tr e a m o n D e m a n d a n d A T M

In In L a bL a b

55

88

......


1 7 1 .6 81 7 1 .6 8

1 7 1 .6 81 7 1 .6 8

......

O u tO u tI/FI/F

00

00

......


33

44

......

In In I/FI/F

11

22

......

1 7 1 .6 8

IPP a c k e t

IPP a c k e t A T

Mc e ll

5

A TM

c e ll

8

A TM

c e ll

8

A TM

c e ll

8

A TM

c e ll

5

A TM

c e ll

3 A TM

c e ll

4 A TM

c e ll

4 A TM

c e ll

4 A TM

c e ll

3

A T M -L S R r e q u e s te d a d d itio n a l la b e l fo r s a m e F E C in o r d e r to d is tin g u is h b e tw e e n in c o m in g in te r fa c e s (D o w n s tr e a m o n D e m a n d )


A T M -L S R s a n dV C -M e r g e

In In L a bL a b

55

88

......


1 7 1 .6 81 7 1 .6 8

1 7 1 .6 81 7 1 .6 8

......

O u tO u tI/FI/F

00

00

......


33

33

......

In In I/FI/F

11

22

......

1 7 1 .6 8

IPP a c k e t

IPP a c k e t A T

Mc e ll

5

A TM

c e ll

8

A TM

c e ll

8

A TM

c e ll

8

A TM

c e ll

5

A TM

c e ll

3 A TM

c e ll

3 A TM

c e ll

3 A TM

c e ll

3 A TM

c e ll

3

A T M -L S R tr a n s m itte d c e lls in s e q u e n c e in o r d e r fo r th e d o w n s tr e a m L S R to r e -a s s e m b lin g c o r r e c tly th e c e lls in to p a c k e ts


L a b e l D is tr ib u tio n P r o to c o ls

• S e v e r a l p r o to c o ls fo r la b e l e x c h a n g eL D P

M a p s u n ic a s t IP d e s tin a tio n s in to la b e ls

R S V P , C R -L D P

U s e d fo r tr a ffic e n g in e e r in g a n d r e s o u r c e r e s e r v a tio n

P IM

F o r m u ltic a s t s ta te s la b e l m a p p in g

B G P

E x te r n a l la b e ls (V P N )


L a b e l r e te n tio n m o d e s

• L ib e r a l r e te n tio n m o d eL S R r e ta in s la b e ls fr o m a ll n e ig h b o u r s

Im p r o v e c o n v e r g e n c e tim e , w h e n n e x t-h o p is a g a in a v a ila b le a fte r IP c o n v e r g e n c e

R e q u ir e m o r e m e m o r y a n d la b e l s p a c e

M a y b e a p r o b le m in A T M -L S R s s in c e a la b e l is a V C

• C o n s e r v a tiv e r e te n tio n m o d eL S R r e ta in s la b e ls o n ly fr o m n e x t-h o p s n e ig h b o u r s

L S R d is c a r d s a ll la b e ls fo r F E C s w ith o u t n e x t-h o p

F r e e m e m o r y a n d la b e l s p a c e


L a b e l D is tr ib u tio nO r d e r e d v s . In d e p e n d e n t

• O r d e r e d L S P c o n tr o l L S R o n ly b in d s a n d a d v e r tis e a la b e l fo r a p a r tic u la r F E C if:

it is th e e g r e s s L S R fo r th a t F E C o r

it h a s a lr e a d y r e c e iv e d a la b e l b in d in g fr o m its n e x t-h o p

• In d e p e n d e n t L S P c o n tr o lL S R b in d s a la b e l to a F E C in d e p e n d e n tly fr o m th e la b e l it h a s to

r e c e iv e fr o m its n e x t-h o p

S im ila r to lin k -s ta te IP r o u tin g (flo o d in g ): e a c h r o u te r b u ild r o u tin g ta b le in d e p e n d e n tly

A n L S R m a y la b e l fo r w a r d p a c k e t to a n e x t-h o p th a t d o e s n o t h a v e y e t la b e l in fo r m a tio n fo r th a t F E C


T h e L a b e l S ta c k

• E a c h p a c k e t/c e ll m a y h a v e m o r e th a n o n e la b e l

• L a b e l s ta c k is th e o r d e r e d lis t o f la b e ls

• A T M c e lls ?L a b e l fo r m a t is n e g o tia te d b e tw e e n p e e r s

V P I/V C I fie ld s m a y c o n ta in d iffe r e n t la b e ls

L a b e l s ta c k is c o p ie d in th e p a y lo a d o f th e F IR S T c e ll o f th e p a c k e t

• L S R n o d e s la b e l s w itc h p a c k e ts b a s e d O N L Y o n th e la b e l a t th e to p o f th e s ta c k


T h e L a b e l S ta c k

1 7 1 .6 8 .1 0 /2 4

R tr -A


In In L a bL a b

55

......


1 7 1 .6 8 .1 01 7 1 .6 8 .1 0

......

O u tO u tI/FI/F

11

......


77

......

In In I/FI/F

00

......

IP p a c k e tD = 1 7 1 .6 8 .1 0 .1 2

L a b e l = 5

L a b e l = 2 1

IP p a c k e tD = 1 7 1 .6 8 .1 0 .1 2

L a b e l = 7

L a b e l = 2 1

• R tr -A fo r w a r d s th e la b e lle d p a c k e t b a s e d o n th e la b e l a t th e to p o f th e la b e l s ta c k


L a b e l s p a c e

• L S R s m u s t b e a b le to d is tin g u is h b e tw e e n la b e lle d p a c k e ts

A la b e l c o r r e s p o n d s to a p a r tic u la r F E C

• L S R c a n d is tr ib u te th e s a m e la b e l/F E C m a p p in g to d iffe r e n t n e ig h b o u r s

• S a m e la b e l c a n b e a s s ig n e d to d iffe r e n t F E C s if a n d o n ly if th e L S R c a n d is tin g u is h th e in te r fa c e fr o m w h ic h th e p a c k e t w ill a r r iv ei.e : th e L S R c a n id e n tify w h o u s th e u p s tr e a m

n e ig h b o u r w h o in s e r t th e la b e l


L a b e l s p a c e

• P e r in te r fa c e la b e l s p a c eL a b e l a r e u n iq u e in a p e r in te r fa c e b a s e

U s e d o v e r A T M in te r fa c e s

L a b e l = V C s

W ith in te r fa c e la b e l s p a c e a n L S R w ill a c c e p t la b e lle d p a c k e ts fo r m u p s tr e a m n e ig h b o u r s o n ly if th e la b e ls h a v e b e e n p r e v io u s ly a d v e r tis e d to th o s e n e ig h b o u r s .

N o la b e l s p o o fin g

U s e fu l w h e n in te r c o n n e c tin g M P L S d o m a in s


L a b e l s p a c e

1 7 1 .6 8 .1 0 /2 4R tr -A


In In L a bL a b

55

55


1 7 1 .6 8 .1 01 7 1 .6 8 .1 0

1 7 1 .6 8 .1 01 7 1 .6 8 .1 0

O u tO u tI/FI/F

22

22


77

88

In In I/FI/F

00

11

IP p a c k e tD = 1 7 1 .6 8 .1 0 .1 2

L a b e l = 5

IP p a c k e tD = 1 7 1 .6 8 .1 0 .1 2

L a b e l = 7

• S a m e la b e l fo r F E C 1 7 1 .1 6 8 .1 0 is a d v e r tis e d to d iffe r e n t u p s tr e a m n e ig h b o u r s

1

02

IP p a c k e tD = 1 7 1 .6 8 .1 0 .1 5

L a b e l = 5

IP p a c k e tD = 1 7 1 .6 8 .1 0 .1 5

L a b e l = 8


L a b e l s p a c e

1 7 1 .6 8 .1 0 /2 4 IP p a c k e t

D = 1 7 1 .6 8 .1 0 .1 2

L a b e l = 5 IP p a c k e t

D = 1 7 1 .6 8 .1 0 .1 2

L a b e l = 7

1

0 2

IP p a c k e tD = 1 7 1 .6 8 .1 0 .1 5

L a b e l = 5

IP p a c k e tD = 1 7 1 .6 8 .1 0 .1 5

L a b e l = 8


In In L a bL a b


O u tO u tI/FI/F


In In I/FI/F

55 1 7 1 .6 8 .1 01 7 1 .6 8 .1 0 22 7700

55 1 7 1 .6 8 .1 01 7 1 .6 8 .1 0 22 8811

55 1 7 1 .6 8 .4 01 7 1 .6 8 .4 0 33 9944

1 7 1 .6 8 .4 0 /2 4

3

IP p a c k e tD = 1 7 1 .6 8 .4 0 .3 3

L a b e l = 9

4

IP p a c k e tD = 1 7 1 .6 8 .4 0 .3 3

L a b e l = 5

S a m e la b e l is a s s ig n e d to d iffe r e n t F E C s if L S R is a b le to d is tin g u is h th e u p s tr e a m n e ig h b o u r w h o s e n t th e p a c k e t


L a b e l s p a c e

1 7 1 .6 8 .1 0 /2 4 IP p a c k e t

D = 1 7 1 .6 8 .1 0 .1 2

L a b e l = 6

1

0 2

IP p a c k e tD = 1 7 1 .6 8 .1 0 .1 5

L a b e l = 6

IP p a c k e tD = 1 7 1 .6 8 .1 0 .1 5

L a b e l = 8


In In L a bL a b


O u tO u tI/FI/F


In In I/FI/F

55 1 7 1 .6 8 .1 01 7 1 .6 8 .1 0 22 7700

66 1 7 1 .6 8 .1 01 7 1 .6 8 .1 0 22 8811

...... ...... ...... ............

P a c k e t is u s in g a la b e l N O T p r e v io u s ly a d v e r tis e d b y th e d o w n s tr e a m n e ig h b o u r

L a b e l n o t b e in g p r e v io u s lya d v e r tis e d to th a t n e ig h b o u r . T h e p a c k e t is d r o p p e d


L a b e l S w itc h P a th (L S P )

• E a c h la b e lle d p a c k e t e n te r s th e M P L S n e tw o r k in th e in g r e s s L S R

e x its th e M P L S n e tw o r k in th e e g r e s s L S R

• L S P is th e s e q u e n c e o f L S R s th r o u g h w h ic h th e la b e lle d p a c k e ts h a v e to g o th r o u g h in o r d e r to r e a c h th e e g r e s s L S R

• L S P e g r e s s n o d e m a y b e th e a g g r e g a tio n p o in t o f p r e fix e s



• L S R -in g r e s s to L S R -e g r e s s p a th is th e s a m e fo r p a c k e ts o f th e s a m e F E C

• L S P s a r e u n id ir e c tio n a lR e tu r n tr a ffic ta k e s a n o th e r L S P

IG P d o m a in w ith a la b e l d is tr ib u tio n p r o to c o l

In g r e s s -L S R

E g r e s s -L S R



• F E C is d e te r m in e d in L S R -in g r e s s

• L S P s d e r iv e fr o m IG P r o u tin g in fo r m a tio n

• L S P s m a y d iv e r g e fr o m IG P s h o r te s t p a thL S P tu n n e ls (e x p lic it r o u tin g ) w ith T r a ffic

E n g in e e r in g

L S P fo llo w s IG P s h o r te s t p a th L S P d iv e r g e s fr o m IG P s h o r te s t p a th




P e n u ltim a te H o p P o p p in g

• T h e la b e l a t th e to p o f th e s ta c k is r e m o v e d (p o p p e d ) b y th e u p s tr e a m n e ig h b o r o f th e e g r e s s L S R

• T h e e g r e s s L S R r e q u e s ts th e “ p o p p in g ” th r o u g h th e la b e l d is tr ib u tio n p r o to c o lE g r e s s L S R a d v e r tis e s im p lic it-n u ll la b e l

• T h e e g r e s s L S R w ill n o t h a v e to d o a lo o k u p a n d r e m o v e its e lf th e la b e lO n e lo o k u p is s a v e d in th e e g r e s s L S R



0 1

S u m m a r y r o u te fo r 1 7 1 .6 8 /1 6

01

1 7 1 .6 8 .1 0 /2 4


In In L a bL a b


O u tO u tI/FI/F


In In I/FI/F

44 1 7 1 .6 8 /1 61 7 1 .6 8 /1 6 22 p o pp o p00

...... ...... ...... ............N e x tN e x t -- H o pH o p

In In L a bL a b


O u tO u tI/FI/F


In In I/FI/F

-- 1 7 1 .6 8 /1 61 7 1 .6 8 /1 6 11 4400

...... ...... ...... ............

E g r e s s L S R s u m m a r is e s m o r es p e c ific r o u te s a n d a d v e r tis e s a la b e l fo r th e n e w F E C

S u m m a r y r o u te is p r o p a g a te th r o u g h th e IG P a n d la b e l is a s s ig n e d b y e a c h L S R

U s e la b e l “ im p lic it-n u ll” fo r F E C 1 7 1 .6 8 /1 6


U s e la b e l 4 fo r F E C 1 7 1 .6 8 /1 6

E g r e s s L S R n e e d s to d o a n IP lo o k u p fo r fin d in g m o r e s p e c ific r o u te

E g r e s s L S R n e e d N O T to r e c e iv e a la b e lle d p a c k e t

la b e lle d w ill h a v e to b e p o p p e d a n y w a y

1 7 1 .6 8 .4 4 /2 4


1 7 1 .6 8 .1 0 /2 41 7 1 .6 8 .1 0 /2 4


1 7 1 .6 8 .9 .11 7 1 .6 8 .9 .1



1 7 1 .6 8 .4 4 /2 41 7 1 .6 8 .4 4 /2 4 1 7 1 .6 8 .1 2 .11 7 1 .6 8 .1 2 .1 S e r ia l2S e r ia l2

1 7 1 .6 8 /1 61 7 1 .6 8 /1 6 ...... N u llN u ll



0 1

IP p a c k e tD = 1 7 1 .6 8 .1 0 .1 5

01

1 7 1 .6 8 .1 0 /2 4


In In L a bL a b


O u tO u tI/FI/F


In In I/FI/F

44 1 7 1 .6 8 /1 61 7 1 .6 8 /1 6 22 p o pp o p00

...... ...... ...... ............N e x tN e x t -- H o pH o p

In In L a bL a b


O u tO u tI/FI/F


In In I/FI/F

-- 1 7 1 .6 8 /1 61 7 1 .6 8 /1 6 11 4400

...... ...... ...... ............

IP p a c k e tD = 1 7 1 .6 8 .1 0 .1 5

L a b e l = 4

IP p a c k e tD = 1 7 1 .6 8 .1 0 .

1 5

P a c k e t a r r iv e s w ith o u t th e la b e la t th e e g r e s s L S R .E g r e s s L S R n e e d s to d o a n IP lo o k u p to m a tc h m o r e s p e c ific r o u te s

IP p a c k e tD = 1 7 1 .6 8 .1 0 .

1 5

P a c k e t is M P L S fo r w a r d e dT o p la b e l is r e m o v e dIP p a c k e t e n te r s th e M P L S n e tw o r k

In g r e s s L S R a s s ig n a la b e l a n dfo r w a r d th e p a c k e t

1 7 1 .6 8 .4 4 /2 4


1 7 1 .6 8 .1 0 /2 41 7 1 .6 8 .1 0 /2 4


1 7 1 .6 8 .9 .11 7 1 .6 8 .9 .1



1 7 1 .6 8 .4 4 /2 41 7 1 .6 8 .4 4 /2 4 1 7 1 .6 8 .1 2 .11 7 1 .6 8 .1 2 .1 S e r ia l2S e r ia l2

1 7 1 .6 8 /1 61 7 1 .6 8 /1 6 ...... N u llN u ll



• A n e x a m p le w ith T r a ffic E n g in e e r in g

T h e to p la b e l c a r r ie s th e p a c k e t a c r o s s th e L S P tu n n e l (h o p -b y -h o p )

If s e c o n d la b e l is p r e s e n t, it is th e n u s e d b y th e e n d p o in t o f th e tu n n e l to fo r w a r d th e p a c k e t a c c o r d in g ly


A g g r e g a tio n

• A s e t o f F E C m a y h a v e th e s a m e n e x t-h o p , s a m e p a th a n d s a m e e g r e s s L S R

• T h e s e F E C s m a y b e g r o u p e d in toa s in g le a g g r e g a te F E C

a s e t o f a g g r e g a te F E C s

• O n e s in g le la b e l w ill b e b o u n d a n d d is tr ib u te d fo r th e a g g r e g a te F E C

• W ith o r d e r e d L S P c o n tr o l u p s tr e a m a n d d o w n s tr e a m L S R s M U S T u s e th e s a m e a g g r e g a tio n g r a n u la r ity


A g g r e g a tio n a n d la y e r 3 s u m m a r is a tio n

• T h e L S R w h ic h d o e s s u m m a r is a tio n w ill b e th e e n d n o d e L S R o f a ll L S P s r e la te d to th e s u m m a r y a d d r e s s

A g g r e g a tio n p o in t

• T h e L S R w ill h a v e to e x a m in e th e s e c o n d le v e l la b e l o f e a c h p a c k e t

If n o s e c o n d la b e l, th e L S R h a s to e x a m in e th e IP h e a d e r

N o s u m m a r is a tio n in A T M -L S R s


A g g r e g a tio n a n d la y e r 3 s u m m a r is a tio n

0 1 01

1 7 1 .6 8 .1 0 /2 4


In In L a bL a b


O u tO u tI/FI/F


In In I/FI/F

-- 1 7 1 .6 8 /1 61 7 1 .6 8 /1 6 11 4400

...... ...... ...... ............


1 7 1 .6 8 .1 0 /2 41 7 1 .6 8 .1 0 /2 4

1 7 1 .6 8 .4 4 /2 41 7 1 .6 8 .4 4 /2 4


1 7 1 .6 8 .9 .11 7 1 .6 8 .9 .1

1 7 1 .6 8 .3 3 .31 7 1 .6 8 .3 3 .3




E g r e s s L S R a d v e r tis e s m o r es p e c ific r o u te s la b e l m a p p in g s

A r e a B o r d e r r o u te r s u m m a r is e s a n d a d v e r tis e sa s in g le la b e l fo r th e s u m m a r y r o u te

L a b e l m a p p in g s fo r1 7 1 .6 8 .1 0 /2 41 7 1 .6 8 .4 4 /2 4


U s e la b e l “ im p lic it-n u ll” fo r F E C 1 7 1 .6 8 /1 6

A g g r e g a tin g L S R n e e d to d o a n IP lo o k u p fo r fin d in g m o r e s p e c ific r o u te

!!!! D o n o t a g g r e g a te in A T M -L S R s !!!!

S p e c ific r o u te s 1 7 1 .6 8 .1 0 /2 41 7 1 .6 8 .4 4 /2 4

1

4

In In L a bL a b


O u tO u tI/FI/F


In In I/FI/F

P o pP o p 1 7 1 .6 8 /1 61 7 1 .6 8 /1 6 N u llN u ll --00

-- 1 7 1 .6 8 .4 4 /2 41 7 1 .6 8 .4 4 /2 4 11 88--

-- 1 7 1 .6 8 .1 0 /2 41 7 1 .6 8 .1 0 /2 4 11 77--


E g r e s s T a r g e te d L a b e l A s s ig n m e n t

• If s e v e r a l F E C s a r e r e a c h a b le th r o u g h th e s a m e e g r e s s L S R In g r e s s L S R m a y u s e th e s a m e la b e l fo r a ll F E C s

L a b e l id e n tifie s th e e g r e s s L S R

U s e d fo r B G P r o u te s

A ll B G P r o u te s h a v in g s a m e n e x t-h o p w ill u s e th e s a m e la b e l id e n tify in g th e n e x t-h o p a d d r e s s

L S P e g r e s s m u s t b e k n o w n a s h o s t r o u te in to th e IG P


R o u te S e le c tio nH o p b y H o p R o u tin g

• A t e a c h h o p th e L S R s e le c ts th e L S P w h e r e to fo r w a r d th e p a c k e t

• S im ila r to IP r o u tin g w h e r e e a c h h o p m a k e s its o w n r o u te s e le c tio n


R o u te S e le c tio nE x p lic it R o u tin g

• T h e in g r e s s L S R h a s th e k n o w le d g e o f th e c o m p le te p a th (L S P ) fo r th e F E C

• T h e in g r e s s L S R s p e c ifie s a ll L S R n o d e s th a t a r e in th e p a th

• T h e L S P c a n b e s e t s ta tic a lly b y c o n fig u r a tio n

• T h e L S P c a n b e s e t d y n a m ic a lly u s in g lin k -s ta te to p o lo g y in fo r m a tio n

• T r a ffic E n g in e e r in g m a k e s u s e o f e x p lic it r o u te d L S P s


R o u te S e le c tio nE x p lic it R o u tin g

• L S R -1 r e q u e s t a n e x p lic it L S P to L S R -5 :

L S R 1 , L S R -2 , L S R -4 , L S R -5

• T h e r e q u e s t tr a v e ls h o p -b y -h o p a n d w h e n it r e a c h e s th e e g r e s s p o in t la b e ls a r e a d v e r tis e d b a c k to th e in g r e s s L S R


L S R -1L S R -2

L S R -4 L S R -5

L S R -3

L S R -6

In g r e s s

E g r e s s

P o p la b e l fo r L S R -5

U s e la b e l 2 5

fo r L S R -5

N e e d la b e ls fo r L S P -1 g o in g th r o u g h

L S R -1L S R -2L S R -4L S R -5

U s e la b e l 3 9

fo r L S R -5


R o u te S e le c tio nE x p lic it R o u tin g a n d la b e l s ta c k

L S R -1L S R -2

L S R -4 L S R -5

L S R -3

L S R -6

In g r e s s

E g r e s s


U s e la b e l 2 5

fo r L S R -5

U s e la b e l 3 9

fo r L S R -5

U s e la b e l 3fo r L S R -6


L S R -1 a n d L S R -5 a r en o n -a d ja c e n t p e e r s fo r la b e l e x c h a n g e

L S R -5 a d v e r tis e s m a p p in g s to L S R -1 a s L S R -1 w a s a n a d ja c e n t n e ig h b o r


R o u te S e le c tio nE x p lic it R o u tin g a n d la b e l s ta c k

L S R -1L S R -2

L S R -4 L S R -5

L S R -3

L S R -6

In g r e s s

E g r e s s

L S R -5 --> 2 5L S R -6 --> 3

IP p a c k e t

L a b e l = 3

L a b e l = 2 5

IP p a c k e t

L a b e l = 9

IP p a c k e t

L a b e l = 3

L a b e l = 3 9

3 9 < -- L S R -5 --> P o p3 < -- L S R -6 --> 9

IP p a c k e t

L a b e l = 3


A T M L S R sL a b e l E n c o d in g

• L a b e l in fo r m a tio n is c a r r ie d in V P I/V C I fie ld w ith d iffe r e n t te c h n iq u e s to e n c o d e la b e ls

• V C e n c o d in gV P I/V C I fie ld u s e d to e n c o d e th e to p la b e l

• V P e n c o d in gV P I fie ld u s e d to e n c o d e th e fir s t la b e l

V C I fie ld u s e d to e n c o d e th e s e c o n d la b e l


A T M L S R s - M e r g e C a p a b ilitie s

• M e r g in g L S RA b ility to u s e th e s a m e la b e l fo r d iffe r e n t

u p s tr e a m n e ig h b o u r s (a n d s a m e F E C )

C e ll in te r le a v e p r o b le m

U p s tr e a m A T M -L S R r e q u e s ts o n e la b e l fo r th e s e F E C s

• N o n m e r g in g L S R sA T M -L S R r e q u e s ts o n e la b e l p e r F E C a n d p e r

in c o m in g in te r fa c e (u p s tr e a m n e ig h b o u r s )

D o w n s tr e a m L S R m a y r e q u e s t its e lf n e w la b e l to its d o w n s tr e a m n e ig h b o u r s


L o o p s a n d T T L

• In IP n e tw o r k s T T L is u s e d to p r e v e n t p a c k e ts to tr a v e l in d e fin ite ly in th e n e tw o r kT T L is d e c r e m e n te d a t e a c h r o u te r -h o p

If T T L = 0 p a c k e t is d is c a r d e d

• M P L S m a y u s e s a m e m e c h a n is m b u t n o t o n a ll e n c a p s u la tio n sT T L is p r e s e n t in th e la b e l h e a d e r fo r P P P a n d

L A N h e a d e r s (s h im h e a d e r s )

A T M c e ll h e a d e r d o e s n o t h a v e T T L



• F o r P P P /L A N e n c a p s u la tio n T T L is u s e d in th e s a m e w a y it is u s e d in IP n e tw o r k s

• W h e n a p a c k e t e n te r s in to th e M P L S n e tw o r k th e L S R s m a y b e c o n fig u r e d in o r d e r toT h e In g r e s s L S R d o e s a c o p y o f th e la y e r 3 T T L in to

th e L a b e l T T L

T T L p r o p a g a tio n

E a c h h o p d e c r e m e n ts T T L

If T T L = 0 p a c k e t is d is c a r d e d

T h e E g r e s s L S R d o e s a c o p y o f th e la b e l T T L in to th e la y e r 3 T T L w h e n th e p a c k e t le a v e s th e M P L S n e tw o r k



• L S R s u s in g A T M o r F R d o n o t h a v e T T L c a p a b ility

• S till w h e n a p a c k e t e m e r g e s fr o m a n L S P it h a s to h a v e a T T L r e fle c tin g th e n u m b e r o f n o d e s it tr a v e r s e d

• L a b e l d is tr ib u tio n p r o to c o ls m a y u s e h o p -c o u n t v a lu e s E a c h n o d e k n o w s th e n u m b e r o f h o p s to

r e a c h th e L S P e n d



• L S R s e x c h a n g e la b e l m a p p in g s w ith h o p -c o u n t in fo r m a tio n


L S R -1L S R -2

L S R -4 L S R -5

L S R -3

L S R -6

In g r e s s

E g r e s s

U s e la b e l 2 1

fo r L S R -6H o p s = 2

U s e la b e l 2 5


U s e la b e l 3 9


P o p la b e l fo r L S R -6H o p s = 1



• T T L is d e c r e m e n te d p r io r to e n te r in g th e n o n -T T L c a p a b le L S P

If T T L is 0 th e p a c k e t is d is c a r d e d a t th e in g r e s s p o in t

• T T L is e x a m in e d a t th e L S P e x it


L S R -1

L S R -2

L S R -4 L S R -5

L S R -3

L S R -6

E g r e s s

IP p a c k e tT T L = 6

L a b e l = 2 5


IP p a c k e tT T L = 1 0

L S R -6 --> 2 5H o p s = 4


L a b e l = 3 9


L a b e l = 2 1


L o o p s a n d P a th V e c to r (L D P )

• L D P p r o to c o l u s e s P a th V e c to r m e c h a n is m to d e te c t lo o p s

• E a c h L S R in s e r ts (a p p e n d ) its ID in to la b e l m a p p in g s m e s s a g e s

• L S R r e c e iv in g a n L D P m e s s a g e w ill c h e c k th e ID lis t

• If its o w n ID is fo u n d th e lo o p is d e te c te d

S im ila r to B G P A S _ P A T H p r o c e s s in g


L D PC o n c e p ts

• L a b e l d is tr ib u tio n p r o c e d u r e s

• U s e d to m a p F E C to la b e ls

F E C : IP n e tw o r k la y e r in fo r m a tio n

• L a b e ls a r e u s e d to c r e a te L a b e l S w itc h P a th s (L S P s )

• L D P w o r k s b e tw e e n p e e r s

• L D P s e s s io n s a r e e s ta b lis h e d b e tw e e n p e e r s

P e e r s n e e d n o t to b e a d ja c e n t


C o n c e p tsL D P M e s s a g e s

• P e e r s e x c h a n g e L D P m e s s a g e s

• D is c o v e r y m e s s a g e s

U s e d to d is c o v e r a n d m a in ta in th e p r e s e n c e o f n e w p e e r s

H e llo p a c k e ts (U D P ) s e n t to a ll-r o u te r s -in -s u b n e t m u ltic a s t a d d r e s s

O n c e n e ig h b o u r is d is c o v e r e d , th e L D P s e s s io n is e s ta b lis h e d o v e r T C P


C o n c e p tsL D P M e s s a g e s

• S e s s io n m e s s a g e s

E s ta b lis h , m a in ta in a n d te r m in a te L D P s e s s io n s

• A d v e r tis e m e n t m e s s a g e s

C r e a te , m o d ify , d e le te la b e l m a p p in g s

• N o tific a tio n m e s s a g e s

E r r o r s ig n a llin g


L D P o p e r a tio n s

• L D P d is tr ib u te m a p p in g s b e tw e e n la b e ls a n d F E C s

• F E C e le m e n ts

IP a d d r e s s p r e fix w ith 0 to 3 2 b its m a s k le n g th

IP h o s t a d d r e s s (3 2 b its m a s k le n g th )


L D P o p e r a tio n sM a p p in g p a c k e ts to L S P s

• P a c k e ts a r e m a p p e d to L S P s a c c o r d in g to fo llo w in g r u le :

P a c k e t is m a p p e d to IP h o s t a d d r e s s F E C e le m e n t

P a c k e t is m a p p e d to e x a c t L S P m a tc h

P a c k e t is m a p p e d to lo n g e s t m a tc h L S P

If p a c k e t h a s to g o to a k n o w n e g r e s s L S R a n d th e r e is a n IP p r e fix (3 2 b its ) fo r th a t e g r e s s n o d e , th e p a c k e t is m a p p e d to th a t L S P


L D P o p e r a tio n sL a b e l S p a c e s

• P e r in te r fa c e la b e l s p a c e

T y p ic a lly fo r A T M in te r fa c e s w h e r e V P I/V C I fie ld s a r e u s e d fo r la b e ls

A llo w s th e u s e o f s a m e la b e l v a lu e s o n d iffe r e n t in te r fa c e s

• P e r p la tfo r m la b e l s p a c e

L a b e ls w ill b e u n iq u e a c r o s s a ll in te r fa c e s o f th e p la tfo r m


L D P o p e r a tio n sId e n tifie r s

• L D P Id e n tifie r6 b y te s id e n tify in g th e L S R a n d th e la b e l s p a c e

4 b y te s : IP a d d r e s s o f o n e o f th e p la tfo r m in te r fa c e s

2 b y te s : L a b e l s p a c e id e n tifie r

< IP a d d r e s s > :< L a b e l s p a c e ID >

L S R u s in g d iffe r e n t la b e l s p a c e s (in te r fa c e ) w ill u s e d iffe r e n t la b e l s p a c e id e n tifie r s :

1 9 2 .0 .3 .5 :1 0

1 9 2 .0 .3 .5 :2 0

• L S R u s in g d iffe r e n t la b e l s p a c e s w ill u s e s e p a r a te L D P s e s s io n s


L D P O p e r a tio n sS e s s io n s

R 1

R 2

R 3

R 4

L 1 L 3

L 2 L 4

R 1 R 2 L 1

L 2

L 3

R 1 R 2 L 1

S e s s io n fo r L 1 , L 2 a n d L 3

R 1

R 2

R 3

R 4

S e s s io n fo r L 1 S e s s io n fo r L 3

S e s s io n fo r L 2 S e s s io n fo r L 4

R 1 R 2 L 1

L 2 (A T M )

L 3

R 1 R 2 S e s s io n fo r L 2

S e s s io n fo r L 1 , L 3


L D P O p e r a tio n sS e s s io n s

• L D P s e s s io n s c a n b e e s ta b lis h e d b e tw e e n n o n d ir e c tly c o n n e c te d n e ig h b o u r s

• M a y b e u s e d fo r T r a ffic E n g in e e r in g p u r p o s e s

• D is c o v e r y m e c h a n is m is d iffe r e n tD ir e c tly c o n n e c te d n e ig h b o u r s

N o n -d ir e c tly c o n n e c te d n e ig h b o u r s


L D P O p e r a tio n sN o n -d ir e c tly c o n n e c te d n e ig h b o u r s

L S R -1L S R -2

L S R -4 L S R -5

L S R -3

L S R -6

In g r e s s

E g r e s s


U s e la b e l 2 5

fo r L S R -5

U s e la b e l 3 9

fo r L S R -5



L S R -1 a n d L S R -5 a r en o n -a d ja c e n t p e e r s fo r la b e l e x c h a n g e

L S R -5 a d v e r tis e s m a p p in g s to L S R -1 a s L S R -1 w a s a n a d ja c e n t n e ig h b o r


L D P O p e r a tio n sD is c o v e r y M e c h a n is m

• D ir e c tly c o n n e c te d n e ig h b o u r s

D is c o v e r e d th r o u g h h e llo p a c k e ts

S e n t to m u ltic a s t a ll-r o u te r s -in -s u b n e t a d d r e s s

• N o n -D ir e c tly c o n n e c te d n e ig h b o u r s

T a r g e te d h e llo p a c k e ts

B y c o n fig u r a tio n , h e llo p a c k e ts a r e s e n t to s p e c ific n e ig h b o u r IP a d d r e s s

D is c o v e r y is a s y m m e tr ic

• O n c e d is c o v e r y is d o n e L D P s e s s io n s a r e e s ta b lis h e d o v e r T C P


C o n fig u r a tio nC o n fig u r a tio n

• C E F s h o u ld b e r u n n in g

• ip c e f c o m m a n d is in g lo b a l m o d e fo r G S R it is d e fa u lt m o d e o f s w itc h in g

• T a g s w itc h in g y o u n e e d to c o n fig u r e it in g lo b a l m o d e

ta g -s w itc h in g ip

m p ls ip


C o n fig u r a tio nC o n fig u r a tio n

• T o e n a b le to ty p e o f la b e l d is tr ib u tio n p r o to c o l y o u w a n t to r u n , th is is d o n e p e r in te r fa c e b a s is

m p ls la b e l-p ro to c o l [ td p ld p b o th ]


C o n tr o llin g L /T D PC o n tr o llin g L /T D P

• O n c e th e ta g -s w itc h in g ip o r m p ls ipc o m m a n d is c o n fig u r e d a ll in te r fa c e s s ta r t to s e n d L /T D P d is c o v e r y p a c k e ts

• C o n tr o l th e L /T D P d is c o v e r y p a c k e t b e in g s e n d o n y o u r c u s to m e r c o n n e c tin g in te r fa c e s


C o n tr o llin g T D PC o n tr o llin g T D P

• E x a m p le

in te rfa c e s e ria l 1 /0

a c c e s s -g ro u p 1 0 1 in

a c c e s s -lis t 1 0 1 d e n y tc p a n y a n y e q 7 1 1

a c c e s s -lis t 1 0 1 p e rm it ip a n y a n y


C o n tr o llin g th e M T UC o n tr o llin g th e M T U

• 4 b y te s o f s h im is a d d e d a t e a c h p a c k e t d e p e n d in g o n s ta c k in g

• M P L S m tu is in c r e a s e d a u to m a tic a lly o n W A N in te r fa c e s

• L A N ’s n e e d to b e c o n fig u r e d


• S o m e d e v ic e s o n y o u r L A N in te r fa c e s m ig h t n o t s u p p o r t ju m b o fr a m e s

• C o m m a n d to s e t th e m tu s iz e isin te rfa c e fa s te th e rn e t 0 /0

m p ls ip

m p ls m tu 1 5 1 2

C o n tr o llin g th e M T UC o n tr o llin g th e M T U


C o n fig u r in g T T LC o n fig u r in g T T L

• B y d e fa u lt ip ttl is c o p ie d in to m p ls p a c k e t

• T o d is a b le y o u n e e d th e fo llo w in g c o m m a n d

n o ta g -s w itc h in g ip p ro p a g a te -ttl

n o m p ls ip p ra p a g a te -ttl

• T T L p r o p a g a tio n if d is a b le d h a s to b e d o n e o n b o th in g r e s s a n d e g r e s s L S R


C o n d itio n a l L a b e l d is tr ib u tio nC o n d itio n a l L a b e l d is tr ib u tio n

• B y d e fa u lt la b e ls fo r a ll d e s tin a tio n s a r e a n n o u n c e d

• L a b e ls a r e d is tr ib u te d to a ll L D P /T D P n e ig h b o r s

• C o n d itio n a l a d v e r tis e m e n t c o u ld b e d o n e fo r fr a m e m o d e

T a g -s w itc h in g a d v e rtis e -ta g s fo r net- a c l to td p - a c l

mpls basics

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