关于差分线 有个问题 高手帮忙看一下

我在allegro里面点了一根差分线的net 想看看它的长度 结果显示

Net Name: DNRXN_1
Via Count: 2
Total Etch Length: 7493.564 MIL
Total Manhattan Length: 7041.8 MIL
Percent Manhattan: 106.42%
Pin Type SigNoise Model
--- ---- --------------
C122.2 UNSPEC
C106.1 UNSPEC
C3153.1 UNSPEC
IC94.C3 UNSPEC
No connections remaining
Properties attached to net
LOGICAL_PATH = @\os6850e p48x 0626 1300\.root(sch_1):dnrxn_1
DIFFP_PHASE_TOL = 10 mil
Electrical Constraints assigned to net
diff pair primary gap: 9 MIL
diff pair line width: 5 MIL
diff pair neck gap: 6 MIL
diff pair neck width: 4 MIL
diff pair phase tolerance: 10 mil
Constraint information:
(DPTol) C106.1 to C3153.1 min= 7435.859 MIL max= 7455.859 MIL actual= 7443.982 MIL
DPData: gap=9.000 (--0.001,+0.000) tolerance= 10.000; max uncoupled= -0.001
(6164.700,7400.100) pin C106.1,UNSPEC,TOP/TOP
(6164.700,7400.100) pin C122.2,UNSPEC,TOP/TOP
41.893 MIL cline TOP
(6199.800,7383.700) via TOP/BOTTOM
7342.998 MIL cline S8
(701.000,5784.000) via TOP/BOTTOM
59.091 MIL cline TOP
(708.031,5832.500) pin C3153.1,UNSPEC,TOP/TOP
Member of Groups:
DIFF_PAIR : DIFFPAIR385


我想问的是 这根net的长度到底是 Total Etch Length: 7493.564 MIL 还是 (DPTol) C106.1 to C3153.1 min= 7435.859 MIL max= 7455.859 MIL actual= 7443.982 MIL 啊

在constraint manager里的total etch length里面 显示的是前一个 但在做DPTol比较的时候是用actual= 7443.982 MIL 这个数值来比较的 为什么会有这个情况呢